MATH 19520/51 Class 8

Size: px
Start display at page:

Download "MATH 19520/51 Class 8"

Transcription

1 MATH 19520/51 Class 8 Minh-Tam Trinh University of Chicago

2 1 Directional derivatives. 2 Gradient vectors. 3 Review level sets. 4 Tangent planes to level surfaces of functions of three variables.

3 Directional Derivatives A displacement vector v can always be rewritten ( ) v (1) v = v. v The scalar v tells us its length and the unit vector v/ v tells us its direction.

4 Directional Derivatives A displacement vector v can always be rewritten ( ) v (1) v = v. v The scalar v tells us its length and the unit vector v/ v tells us its direction. Examples of unit vectors in R 2 : (2) (1, 0), ( 3 5, 4 5 ), (0, 1), ( 1, 0), ( 1 2, 1 2 ).

5 If f is a function of x and y, then f x, resp. f y, is the change in f per unit length in the direction of (1, 0), resp. (0, 1).

6 If f is a function of x and y, then f x, resp. f y, is the change in f per unit length in the direction of (1, 0), resp. (0, 1). But what s the change per unit length in the direction of ( 3 5, 4 5 )?

7 If f is a function of x and y, then f x, resp. f y, is the change in f per unit length in the direction of (1, 0), resp. (0, 1). But what s the change per unit length in the direction of ( 3 5, 4 5 )? By proportionality, we want (3) 3/5ths of the change per unit length in the (1, 0)-direction + 4/5ths of the change per unit length in the (0, 1)-direction. That is, f x (3/5) + f y (4/5).

8 If u = (u 1, u 2 ) R 2 is a unit vector, then the derivative of f (x, y) in the direction of u is (4) D u f = f x u 1 + f y u 2. Formally, (5) D u f (x, y) = lim ɛ 0 f (x + u 1 ɛ, y + u 2 ɛ) f (x, y) ɛ assuming the limit exists.

9 Example (Stewart, 14.6, Example 2) Let f (x, y) = x 3 3xy + 4y 2, and let u R 2 be the unit vector at an angle of π/6 counterclockwise from (1, 0). Find u and D u f (1, 2).

10 Example (Stewart, 14.6, Example 2) Let f (x, y) = x 3 3xy + 4y 2, and let u R 2 be the unit vector at an angle of π/6 counterclockwise from (1, 0). Find u and D u f (1, 2). If u = (a, b), then a = cos(π/6) = 3/2 and b = sin(π/6) = 1/2.

11 Example (Stewart, 14.6, Example 2) Let f (x, y) = x 3 3xy + 4y 2, and let u R 2 be the unit vector at an angle of π/6 counterclockwise from (1, 0). Find u and D u f (1, 2). If u = (a, b), then a = cos(π/6) = 3/2 and b = sin(π/6) = 1/2. Since f x = 3x 2 3y and f y = 3x + 8y, we compute f x (1, 2) = 3 and f y (1, 2) = 13. Then (6) D u f (1, 2) = =

12 The graph of z = x 3 3xy + 4y 2.

13 In general, if f is a function of n variables x 1,..., x n, then the derivative of f in the direction of u = (u 1,..., u n ) is (7) D u f = n i=1 f x i u i. Do you see how to write this sum as a dot product?

14 Gradient Vectors If f is a function of x 1,..., x n, then the gradient of f is ( f f =,..., f ) (8). x 1 x n (Pronounced grad f or del f or nabla f. ) This is a vector function, i.e., a function whose output is a vector not a number.

15 Gradient Vectors If f is a function of x 1,..., x n, then the gradient of f is ( f f =,..., f ) (8). x 1 x n (Pronounced grad f or del f or nabla f. ) This is a vector function, i.e., a function whose output is a vector not a number. We have (9) D u f = f u for any unit vector u.

16 Theorem The gradient f points in the direction of the unit vector u that maximizes the directional derivative D u f.

17 Theorem The gradient f points in the direction of the unit vector u that maximizes the directional derivative D u f. Proof. By the angle formula for dot product, (10) D u f = f u cos θ = f cos θ, where θ is the angle between f and u. The right-hand side is maximized when θ = 0.

18 Example Let f (x, y) = xe y. Find the maximum directional derivative of f at (2, 0), and (the unit vector in) the direction where it occurs.

19 Example Let f (x, y) = xe y. Find the maximum directional derivative of f at (2, 0), and (the unit vector in) the direction where it occurs. We compute f (x, y) = (e y, xe y ), from which f (2, 0) = (1, 2). This has the same direction as the unit vector (1,2) (1,2) = ( 1, 5 2 ). 5

20 Example Let f (x, y) = xe y. Find the maximum directional derivative of f at (2, 0), and (the unit vector in) the direction where it occurs. We compute f (x, y) = (e y, xe y ), from which f (2, 0) = (1, 2). This has the same direction as the unit vector (1,2) (1,2) = ( 1, 5 2 ). 5 This is the direction of the maximum directional derivative, so we compute (11) D (1/ 5, 2/ 5) f = (1, 2) ( 1 5, 2 5 ) = 5.

21 Geometry of the Gradient Moving along the gradient gives maximum rate of change. Moving along/within a level set gives zero rate of change.

22 Geometry of the Gradient Moving along the gradient gives maximum rate of change. Moving along/within a level set gives zero rate of change. Within the domain of f, gradients are locally orthogonal to level sets.

23 Review of Level Sets Remember... 1 A function of two variables x, y has level curves in the (x, y)-plane. 2 A function of three variables x, y, z has level surfaces in (x, y, z)-space.

24 Try to imagine/draw the function f (x, y) = x 3 + y 2.

25 Try to imagine/draw the function f (x, y) = x 3 + y 2. Some of its level curves in the (x, y)-plane:

26 Now imagine the function F (x, y, z) = xy z 2.

27 Now imagine the function F (x, y, z) = xy z 2. Here are the upper halves of some of its level surfaces in (x, y, z)-space:

28 Tangent Planes to Level Surfaces of 3-Variable Functions Earlier, we learned how to find tangent planes to graphs in (x, y, z)-space of functions in two variables x and y. Now, we will learn how to find tangent planes to level surfaces in (x, y, z)-space of functions in three variables x, y, z. Warning! Do not confuse these procedures!

29 Let S = {(x, y, z) R 3 : F (x, y, z) = α} be a level surface, and let (a, b, c) be a point on this surface, i.e., g(a, b, c) = α.

30 Let S = {(x, y, z) R 3 : F (x, y, z) = α} be a level surface, and let (a, b, c) be a point on this surface, i.e., g(a, b, c) = α. The coordinate equation of the tangent plane to S at (a, b, c) is: (12) F x (a, b, c)(x a) + F y (a, b, c)(y b) + F z (a, b, c)(z c) = 0.

31 Let S = {(x, y, z) R 3 : F (x, y, z) = α} be a level surface, and let (a, b, c) be a point on this surface, i.e., g(a, b, c) = α. The coordinate equation of the tangent plane to S at (a, b, c) is: (12) F x (a, b, c)(x a) + F y (a, b, c)(y b) + F z (a, b, c)(z c) = 0. Taking u = (x, y, z), the corresponding vector equation is (13) F (a, b, c) ( u (a, b, c)) = 0.

32 Example (Stewart, 14.6, Example 8) Find a coordinate equation for the tangent plane to the ellipsoid x y2 + z2 9 = 3 at ( 2, 1, 3).

33 Example (Stewart, 14.6, Example 8) Find a coordinate equation for the tangent plane to the ellipsoid x y2 + z2 9 = 3 at ( 2, 1, 3). Set F (x, y, z) = x2 4 + y2 + z2 9. Then (14) F (x, y, z) = ( ) x 2z, 2y,, 2 9 so F ( 2, 1, 3) = ( 1, 2, 2 3 ). We get the coordinate equation (15) 1(x + 2) + 2(y 1) 2 (z + 3) = 0. 3 It simplifies to x + 2y 2 3 z = 6.

34 The lower half of the ellipsoid x2 4 + y2 + z2 9 = 3.

Gradient and Directional Derivatives

Gradient and Directional Derivatives Gradient and Directional Derivatives MATH 311, Calculus III J. Robert Buchanan Department of Mathematics Fall 2011 Background Given z = f (x, y) we understand that f : gives the rate of change of z in

More information

MATH 19520/51 Class 6

MATH 19520/51 Class 6 MATH 19520/51 Class 6 Minh-Tam Trinh University of Chicago 2017-10-06 1 Review partial derivatives. 2 Review equations of planes. 3 Review tangent lines in single-variable calculus. 4 Tangent planes to

More information

Functions of Several Variables

Functions of Several Variables Functions of Several Variables Directional Derivatives and the Gradient Vector Philippe B Laval KSU April 7, 2012 Philippe B Laval (KSU) Functions of Several Variables April 7, 2012 1 / 19 Introduction

More information

Directional Derivatives. Directional Derivatives. Directional Derivatives. Directional Derivatives. Directional Derivatives. Directional Derivatives

Directional Derivatives. Directional Derivatives. Directional Derivatives. Directional Derivatives. Directional Derivatives. Directional Derivatives Recall that if z = f(x, y), then the partial derivatives f x and f y are defined as and represent the rates of change of z in the x- and y-directions, that is, in the directions of the unit vectors i and

More information

Kevin James. MTHSC 206 Section 15.6 Directional Derivatives and the Gra

Kevin James. MTHSC 206 Section 15.6 Directional Derivatives and the Gra MTHSC 206 Section 15.6 Directional Derivatives and the Gradient Vector Definition We define the directional derivative of the function f (x, y) at the point (x 0, y 0 ) in the direction of the unit vector

More information

To graph the point (r, θ), simply go out r units along the initial ray, then rotate through the angle θ. The point (1, 5π 6

To graph the point (r, θ), simply go out r units along the initial ray, then rotate through the angle θ. The point (1, 5π 6 Polar Coordinates Any point in the plane can be described by the Cartesian coordinates (x, y), where x and y are measured along the corresponding axes. However, this is not the only way to represent points

More information

14.6 Directional Derivatives and the Gradient Vector

14.6 Directional Derivatives and the Gradient Vector 14 Partial Derivatives 14.6 and the Gradient Vector Copyright Cengage Learning. All rights reserved. Copyright Cengage Learning. All rights reserved. and the Gradient Vector In this section we introduce

More information

d f(g(t), h(t)) = x dt + f ( y dt = 0. Notice that we can rewrite the relationship on the left hand side of the equality using the dot product: ( f

d f(g(t), h(t)) = x dt + f ( y dt = 0. Notice that we can rewrite the relationship on the left hand side of the equality using the dot product: ( f Gradients and the Directional Derivative In 14.3, we discussed the partial derivatives f f and, which tell us the rate of change of the x y height of the surface defined by f in the x direction and the

More information

f for Directional Derivatives and Gradient The gradient vector is calculated using partial derivatives of the function f(x,y).

f for Directional Derivatives and Gradient The gradient vector is calculated using partial derivatives of the function f(x,y). Directional Derivatives and Gradient The gradient vector is calculated using partial derivatives of the function f(x,y). For a function f(x,y), the gradient vector, denoted as f (pronounced grad f ) is

More information

Math 21a Tangent Lines and Planes Fall, What do we know about the gradient f? Tangent Lines to Curves in the Plane.

Math 21a Tangent Lines and Planes Fall, What do we know about the gradient f? Tangent Lines to Curves in the Plane. Math 21a Tangent Lines and Planes Fall, 2016 What do we know about the gradient f? Tangent Lines to Curves in the Plane. 1. For each of the following curves, find the tangent line to the curve at the point

More information

What you will learn today

What you will learn today What you will learn today Tangent Planes and Linear Approximation and the Gradient Vector Vector Functions 1/21 Recall in one-variable calculus, as we zoom in toward a point on a curve, the graph becomes

More information

To graph the point (r, θ), simply go out r units along the initial ray, then rotate through the angle θ. The point (1, 5π 6. ) is graphed below:

To graph the point (r, θ), simply go out r units along the initial ray, then rotate through the angle θ. The point (1, 5π 6. ) is graphed below: Polar Coordinates Any point in the plane can be described by the Cartesian coordinates (x, y), where x and y are measured along the corresponding axes. However, this is not the only way to represent points

More information

Jim Lambers MAT 169 Fall Semester Lecture 33 Notes

Jim Lambers MAT 169 Fall Semester Lecture 33 Notes Jim Lambers MAT 169 Fall Semester 2009-10 Lecture 33 Notes These notes correspond to Section 9.3 in the text. Polar Coordinates Throughout this course, we have denoted a point in the plane by an ordered

More information

Quiz 6 Practice Problems

Quiz 6 Practice Problems Quiz 6 Practice Problems Practice problems are similar, both in difficulty and in scope, to the type of problems you will see on the quiz. Problems marked with a are for your entertainment and are not

More information

x 6 + λ 2 x 6 = for the curve y = 1 2 x3 gives f(1, 1 2 ) = λ actually has another solution besides λ = 1 2 = However, the equation λ

x 6 + λ 2 x 6 = for the curve y = 1 2 x3 gives f(1, 1 2 ) = λ actually has another solution besides λ = 1 2 = However, the equation λ Math 0 Prelim I Solutions Spring 010 1. Let f(x, y) = x3 y for (x, y) (0, 0). x 6 + y (4 pts) (a) Show that the cubic curves y = x 3 are level curves of the function f. Solution. Substituting y = x 3 in

More information

MATH 2400, Analytic Geometry and Calculus 3

MATH 2400, Analytic Geometry and Calculus 3 MATH 2400, Analytic Geometry and Calculus 3 List of important Definitions and Theorems 1 Foundations Definition 1. By a function f one understands a mathematical object consisting of (i) a set X, called

More information

MATH Harrell. Which way is up? Lecture 9. Copyright 2008 by Evans M. Harrell II.

MATH Harrell. Which way is up? Lecture 9. Copyright 2008 by Evans M. Harrell II. MATH 2401 - Harrell Which way is up? Lecture 9 Copyright 2008 by Evans M. Harrell II. A set does not necessarily have boundaries If it does have boundaries Are the boundaries part of the set or not? Sets

More information

3.6 Directional Derivatives and the Gradient Vector

3.6 Directional Derivatives and the Gradient Vector 288 CHAPTER 3. FUNCTIONS OF SEVERAL VARIABLES 3.6 Directional Derivatives and te Gradient Vector 3.6.1 Functions of two Variables Directional Derivatives Let us first quickly review, one more time, te

More information

GEOMETRY IN THREE DIMENSIONS

GEOMETRY IN THREE DIMENSIONS 1 CHAPTER 5. GEOMETRY IN THREE DIMENSIONS 1 INSTITIÚID TEICNEOLAÍOCHTA CHEATHARLACH INSTITUTE OF TECHNOLOGY CARLOW GEOMETRY IN THREE DIMENSIONS Contents 1 Geometry in R 3 2 1.1 Lines...............................................

More information

Lagrange multipliers October 2013

Lagrange multipliers October 2013 Lagrange multipliers 14.8 14 October 2013 Example: Optimization with constraint. Example: Find the extreme values of f (x, y) = x + 2y on the ellipse 3x 2 + 4y 2 = 3. 3/2 1 1 3/2 Example: Optimization

More information

Directional Derivatives and the Gradient Vector Part 2

Directional Derivatives and the Gradient Vector Part 2 Directional Derivatives and the Gradient Vector Part 2 Lecture 25 February 28, 2007 Recall Fact Recall Fact If f is a dierentiable function of x and y, then f has a directional derivative in the direction

More information

Lagrange multipliers 14.8

Lagrange multipliers 14.8 Lagrange multipliers 14.8 14 October 2013 Example: Optimization with constraint. Example: Find the extreme values of f (x, y) = x + 2y on the ellipse 3x 2 + 4y 2 = 3. 3/2 Maximum? 1 1 Minimum? 3/2 Idea:

More information

Background for Surface Integration

Background for Surface Integration Background for urface Integration 1 urface Integrals We have seen in previous work how to define and compute line integrals in R 2. You should remember the basic surface integrals that we will need to

More information

MATH 19520/51 Class 10

MATH 19520/51 Class 10 MATH 19520/51 Class 10 Minh-Tam Trinh University of Chicago 2017-10-16 1 Method of Lagrange multipliers. 2 Examples of Lagrange multipliers. The Problem The ingredients: 1 A set of parameters, say x 1,...,

More information

Outcomes List for Math Multivariable Calculus (9 th edition of text) Spring

Outcomes List for Math Multivariable Calculus (9 th edition of text) Spring Outcomes List for Math 200-200935 Multivariable Calculus (9 th edition of text) Spring 2009-2010 The purpose of the Outcomes List is to give you a concrete summary of the material you should know, and

More information

14.5 Directional Derivatives and the Gradient Vector

14.5 Directional Derivatives and the Gradient Vector 14.5 Directional Derivatives and the Gradient Vector 1. Directional Derivatives. Recall z = f (x, y) and the partial derivatives f x and f y are defined as f (x 0 + h, y 0 ) f (x 0, y 0 ) f x (x 0, y 0

More information

3. The three points (2, 4, 1), (1, 2, 2) and (5, 2, 2) determine a plane. Which of the following points is in that plane?

3. The three points (2, 4, 1), (1, 2, 2) and (5, 2, 2) determine a plane. Which of the following points is in that plane? Math 4 Practice Problems for Midterm. A unit vector that is perpendicular to both V =, 3, and W = 4,, is (a) V W (b) V W (c) 5 6 V W (d) 3 6 V W (e) 7 6 V W. In three dimensions, the graph of the equation

More information

Directional Derivatives and the Gradient Vector Part 2

Directional Derivatives and the Gradient Vector Part 2 Directional Derivatives and the Gradient Vector Part 2 Marius Ionescu October 26, 2012 Marius Ionescu () Directional Derivatives and the Gradient Vector Part October 2 26, 2012 1 / 12 Recall Fact Marius

More information

Ch. 7.4, 7.6, 7.7: Complex Numbers, Polar Coordinates, ParametricFall equations / 17

Ch. 7.4, 7.6, 7.7: Complex Numbers, Polar Coordinates, ParametricFall equations / 17 Ch. 7.4, 7.6, 7.7: Complex Numbers, Polar Coordinates, Parametric equations Johns Hopkins University Fall 2014 Ch. 7.4, 7.6, 7.7: Complex Numbers, Polar Coordinates, ParametricFall equations 2014 1 / 17

More information

Math (Spring 2009): Lecture 5 Planes. Parametric equations of curves and lines

Math (Spring 2009): Lecture 5 Planes. Parametric equations of curves and lines Math 18.02 (Spring 2009): Lecture 5 Planes. Parametric equations of curves and lines February 12 Reading Material: From Simmons: 17.1 and 17.2. Last time: Square Systems. Word problem. How many solutions?

More information

12.7 Tangent Planes and Normal Lines

12.7 Tangent Planes and Normal Lines .7 Tangent Planes and Normal Lines Tangent Plane and Normal Line to a Surface Suppose we have a surface S generated by z f(x,y). We can represent it as f(x,y)-z 0 or F(x,y,z) 0 if we wish. Hence we can

More information

Vectors and the Geometry of Space

Vectors and the Geometry of Space Vectors and the Geometry of Space In Figure 11.43, consider the line L through the point P(x 1, y 1, z 1 ) and parallel to the vector. The vector v is a direction vector for the line L, and a, b, and c

More information

MATH 2400: CALCULUS 3 MAY 9, 2007 FINAL EXAM

MATH 2400: CALCULUS 3 MAY 9, 2007 FINAL EXAM MATH 4: CALCULUS 3 MAY 9, 7 FINAL EXAM I have neither given nor received aid on this exam. Name: 1 E. Kim................ (9am) E. Angel.............(1am) 3 I. Mishev............ (11am) 4 M. Daniel...........

More information

Math 142 Fall 2000 Rotation of Axes. In section 11.4, we found that every equation of the form. (1) Ax 2 + Cy 2 + Dx + Ey + F =0,

Math 142 Fall 2000 Rotation of Axes. In section 11.4, we found that every equation of the form. (1) Ax 2 + Cy 2 + Dx + Ey + F =0, Math 14 Fall 000 Rotation of Axes In section 11.4, we found that every equation of the form (1) Ax + Cy + Dx + Ey + F =0, with A and C not both 0, can be transformed by completing the square into a standard

More information

302 CHAPTER 3. FUNCTIONS OF SEVERAL VARIABLES. 4. Function of several variables, their domain. 6. Limit of a function of several variables

302 CHAPTER 3. FUNCTIONS OF SEVERAL VARIABLES. 4. Function of several variables, their domain. 6. Limit of a function of several variables 302 CHAPTER 3. FUNCTIONS OF SEVERAL VARIABLES 3.8 Chapter Review 3.8.1 Concepts to Know You should have an understanding of, and be able to explain the concepts listed below. 1. Boundary and interior points

More information

Directional Derivatives as Vectors

Directional Derivatives as Vectors Directional Derivatives as Vectors John Ganci 1 Al Lehnen 2 1 Richland College Dallas, TX jganci@dcccd.edu 2 Madison Area Technical College Madison, WI alehnen@matcmadison.edu Statement of problem We are

More information

we wish to minimize this function; to make life easier, we may minimize

we wish to minimize this function; to make life easier, we may minimize Optimization and Lagrange Multipliers We studied single variable optimization problems in Calculus 1; given a function f(x), we found the extremes of f relative to some constraint. Our ability to find

More information

MATH 200 (Fall 2016) Exam 1 Solutions (a) (10 points) Find an equation of the sphere with center ( 2, 1, 4).

MATH 200 (Fall 2016) Exam 1 Solutions (a) (10 points) Find an equation of the sphere with center ( 2, 1, 4). MATH 00 (Fall 016) Exam 1 Solutions 1 1. (a) (10 points) Find an equation of the sphere with center (, 1, 4). (x ( )) + (y 1) + (z ( 4)) 3 (x + ) + (y 1) + (z + 4) 9 (b) (10 points) Find an equation of

More information

Math 206 First Midterm October 5, 2012

Math 206 First Midterm October 5, 2012 Math 206 First Midterm October 5, 2012 Name: EXAM SOLUTIONS Instructor: Section: 1. Do not open this exam until you are told to do so. 2. This exam has 8 pages including this cover AND IS DOUBLE SIDED.

More information

Surfaces and Partial Derivatives

Surfaces and Partial Derivatives Surfaces and James K. Peterson Department of Biological Sciences and Department of Mathematical Sciences Clemson University November 15, 2017 Outline 1 2 Tangent Planes Let s go back to our simple surface

More information

Math 136 Exam 1 Practice Problems

Math 136 Exam 1 Practice Problems Math Exam Practice Problems. Find the surface area of the surface of revolution generated by revolving the curve given by around the x-axis? To solve this we use the equation: In this case this translates

More information

MATH 19520/51 Class 15

MATH 19520/51 Class 15 MATH 19520/51 Class 15 Minh-Tam Trinh University of Chicago 2017-11-01 1 Change of variables in two dimensions. 2 Double integrals via change of variables. Change of Variables Slogan: An n-variable substitution

More information

Workbook. MAT 397: Calculus III

Workbook. MAT 397: Calculus III Workbook MAT 397: Calculus III Instructor: Caleb McWhorter Name: Summer 2017 Contents Preface..................................................... 2 1 Spatial Geometry & Vectors 3 1.1 Basic n Euclidean

More information

Math 213 Exam 2. Each question is followed by a space to write your answer. Please write your answer neatly in the space provided.

Math 213 Exam 2. Each question is followed by a space to write your answer. Please write your answer neatly in the space provided. Math 213 Exam 2 Name: Section: Do not remove this answer page you will return the whole exam. You will be allowed two hours to complete this test. No books or notes may be used other than a onepage cheat

More information

Hw 4 Due Feb 22. D(fg) x y z (

Hw 4 Due Feb 22. D(fg) x y z ( Hw 4 Due Feb 22 2.2 Exercise 7,8,10,12,15,18,28,35,36,46 2.3 Exercise 3,11,39,40,47(b) 2.4 Exercise 6,7 Use both the direct method and product rule to calculate where f(x, y, z) = 3x, g(x, y, z) = ( 1

More information

HOMEWORK ASSIGNMENT #4, MATH 253

HOMEWORK ASSIGNMENT #4, MATH 253 HOMEWORK ASSIGNMENT #4, MATH 253. Prove that the following differential equations are satisfied by the given functions: (a) 2 u 2 + 2 u y 2 + 2 u z 2 =0,whereu =(x2 + y 2 + z 2 ) /2. (b) x w + y w y +

More information

Math 113 Calculus III Final Exam Practice Problems Spring 2003

Math 113 Calculus III Final Exam Practice Problems Spring 2003 Math 113 Calculus III Final Exam Practice Problems Spring 23 1. Let g(x, y, z) = 2x 2 + y 2 + 4z 2. (a) Describe the shapes of the level surfaces of g. (b) In three different graphs, sketch the three cross

More information

Let and be a differentiable function. Let Then be the level surface given by

Let and be a differentiable function. Let Then be the level surface given by Module 12 : Total differential, Tangent planes and normals Lecture 35 : Tangent plane and normal [Section 35.1] > Objectives In this section you will learn the following : The notion tangent plane to a

More information

Engineering Mathematics (4)

Engineering Mathematics (4) Engineering Mathematics (4) Zhang, Xinyu Department of Computer Science and Engineering, Ewha Womans University, Seoul, Korea zhangxy@ewha.ac.kr Example With respect to parameter: s (arc length) r( t)

More information

MAT203 OVERVIEW OF CONTENTS AND SAMPLE PROBLEMS

MAT203 OVERVIEW OF CONTENTS AND SAMPLE PROBLEMS MAT203 OVERVIEW OF CONTENTS AND SAMPLE PROBLEMS MAT203 covers essentially the same material as MAT201, but is more in depth and theoretical. Exam problems are often more sophisticated in scope and difficulty

More information

REVIEW I MATH 254 Calculus IV. Exam I (Friday, April 29) will cover sections

REVIEW I MATH 254 Calculus IV. Exam I (Friday, April 29) will cover sections REVIEW I MATH 254 Calculus IV Exam I (Friday, April 29 will cover sections 14.1-8. 1. Functions of multivariables The definition of multivariable functions is similar to that of functions of one variable.

More information

MATH 116 REVIEW PROBLEMS for the FINAL EXAM

MATH 116 REVIEW PROBLEMS for the FINAL EXAM MATH 116 REVIEW PROBLEMS for the FINAL EXAM The following questions are taken from old final exams of various calculus courses taught in Bilkent University 1. onsider the line integral (2xy 2 z + y)dx

More information

Date: 16 July 2016, Saturday Time: 14:00-16:00 STUDENT NO:... Math 102 Calculus II Midterm Exam II Solutions TOTAL. Please Read Carefully:

Date: 16 July 2016, Saturday Time: 14:00-16:00 STUDENT NO:... Math 102 Calculus II Midterm Exam II Solutions TOTAL. Please Read Carefully: Date: 16 July 2016, Saturday Time: 14:00-16:00 NAME:... STUDENT NO:... YOUR DEPARTMENT:... Math 102 Calculus II Midterm Exam II Solutions 1 2 3 4 TOTAL 25 25 25 25 100 Please do not write anything inside

More information

Tangent Planes and Linear Approximations

Tangent Planes and Linear Approximations February 21, 2007 Tangent Planes Tangent Planes Let S be a surface with equation z = f (x, y). Tangent Planes Let S be a surface with equation z = f (x, y). Let P(x 0, y 0, z 0 ) be a point on S. Tangent

More information

Topic 2.3: Tangent Planes, Differentiability, and Linear Approximations. Textbook: Section 14.4

Topic 2.3: Tangent Planes, Differentiability, and Linear Approximations. Textbook: Section 14.4 Topic 2.3: Tangent Planes, Differentiability, and Linear Approximations Textbook: Section 14.4 Warm-Up: Graph the Cone & the Paraboloid paraboloid f (x, y) = x 2 + y 2 cone g(x, y) = x 2 + y 2 Do you notice

More information

Topic 1.6: Lines and Planes

Topic 1.6: Lines and Planes Math 275 Notes (Ultman) Topic 1.6: Lines and Planes Textbook Section: 12.5 From the Toolbox (what you need from previous classes): Plotting points, sketching vectors. Be able to find the component form

More information

Surfaces and Partial Derivatives

Surfaces and Partial Derivatives Surfaces and Partial Derivatives James K. Peterson Department of Biological Sciences and Department of Mathematical Sciences Clemson University November 9, 2016 Outline Partial Derivatives Tangent Planes

More information

MATH 2023 Multivariable Calculus

MATH 2023 Multivariable Calculus MATH 2023 Multivariable Calculus Problem Sets Note: Problems with asterisks represent supplementary informations. You may want to read their solutions if you like, but you don t need to work on them. Set

More information

TEST 3 REVIEW DAVID BEN MCREYNOLDS

TEST 3 REVIEW DAVID BEN MCREYNOLDS TEST 3 REVIEW DAVID BEN MCREYNOLDS 1. Vectors 1.1. Form the vector starting at the point P and ending at the point Q: P = (0, 0, 0), Q = (1,, 3). P = (1, 5, 3), Q = (8, 18, 0). P = ( 3, 1, 1), Q = (, 4,

More information

MATH. 2153, Spring 16, MWF 12:40 p.m. QUIZ 1 January 25, 2016 PRINT NAME A. Derdzinski Show all work. No calculators. The problem is worth 10 points.

MATH. 2153, Spring 16, MWF 12:40 p.m. QUIZ 1 January 25, 2016 PRINT NAME A. Derdzinski Show all work. No calculators. The problem is worth 10 points. MATH. 2153, Spring 16, MWF 12:40 p.m. QUIZ 1 January 25, 2016 PRINT NAME A. Derdzinski Show all work. No calculators. The problem is worth 10 points. 1. Evaluate the area A of the triangle with the vertices

More information

by Kevin M. Chevalier

by Kevin M. Chevalier Precalculus Review Handout.4 Trigonometric Functions: Identities, Graphs, and Equations, Part I by Kevin M. Chevalier Angles, Degree and Radian Measures An angle is composed of: an initial ray (side) -

More information

Lecture 6: Chain rule, Mean Value Theorem, Tangent Plane

Lecture 6: Chain rule, Mean Value Theorem, Tangent Plane Lecture 6: Chain rule, Mean Value Theorem, Tangent Plane Rafikul Alam Department of Mathematics IIT Guwahati Chain rule Theorem-A: Let x : R R n be differentiable at t 0 and f : R n R be differentiable

More information

UNIVERSIDAD CARLOS III DE MADRID MATHEMATICS II EXERCISES (SOLUTIONS ) CHAPTER 3: Partial derivatives and differentiation

UNIVERSIDAD CARLOS III DE MADRID MATHEMATICS II EXERCISES (SOLUTIONS ) CHAPTER 3: Partial derivatives and differentiation UNIVERSIDAD CARLOS III DE MADRID MATHEMATICS II EXERCISES SOLUTIONS ) 3-1. Find, for the following functions: a) fx, y) x cos x sin y. b) fx, y) e xy. c) fx, y) x + y ) lnx + y ). CHAPTER 3: Partial derivatives

More information

MATH 261 EXAM I PRACTICE PROBLEMS

MATH 261 EXAM I PRACTICE PROBLEMS MATH 261 EXAM I PRACTICE PROBLEMS These practice problems are pulled from actual midterms in previous semesters. Exam 1 typically has 6 problems on it, with no more than one problem of any given type (e.g.,

More information

The directional derivative of f x, y in the direction of at x, y u. f x sa y sb f x y (, ) (, ) 0 0 y 0 0

The directional derivative of f x, y in the direction of at x, y u. f x sa y sb f x y (, ) (, ) 0 0 y 0 0 Review: 0, lim D f u 0 0 0 0 u The directional derivative of f, in the direction of at, is denoted b D f, : u a, b must a unit vector u f sa sb f s 0 (, ) (, ) s f (, ) a f (, ) b 0 0 0 0 0 0 D f, f u

More information

= w. w u. u ; u + w. x x. z z. y y. v + w. . Remark. The formula stated above is very important in the theory of. surface integral.

= w. w u. u ; u + w. x x. z z. y y. v + w. . Remark. The formula stated above is very important in the theory of. surface integral. 1 Chain rules 2 Directional derivative 3 Gradient Vector Field 4 Most Rapid Increase 5 Implicit Function Theorem, Implicit Differentiation 6 Lagrange Multiplier 7 Second Derivative Test Theorem Suppose

More information

Answers to practice questions for Midterm 1

Answers to practice questions for Midterm 1 Answers to practice questions for Midterm Paul Hacking /5/9 (a The RREF (reduced row echelon form of the augmented matrix is So the system of linear equations has exactly one solution given by x =, y =,

More information

Constrained Optimization and Lagrange Multipliers

Constrained Optimization and Lagrange Multipliers Constrained Optimization and Lagrange Multipliers MATH 311, Calculus III J. Robert Buchanan Department of Mathematics Fall 2011 Constrained Optimization In the previous section we found the local or absolute

More information

Partial Derivatives. Partial Derivatives. Partial Derivatives. Partial Derivatives. Partial Derivatives. Partial Derivatives

Partial Derivatives. Partial Derivatives. Partial Derivatives. Partial Derivatives. Partial Derivatives. Partial Derivatives In general, if f is a function of two variables x and y, suppose we let only x vary while keeping y fixed, say y = b, where b is a constant. By the definition of a derivative, we have Then we are really

More information

Pre-Calculus Guided Notes: Chapter 10 Conics. A circle is

Pre-Calculus Guided Notes: Chapter 10 Conics. A circle is Name: Pre-Calculus Guided Notes: Chapter 10 Conics Section Circles A circle is _ Example 1 Write an equation for the circle with center (3, ) and radius 5. To do this, we ll need the x1 y y1 distance formula:

More information

Conics, Parametric Equations, and Polar Coordinates. Copyright Cengage Learning. All rights reserved.

Conics, Parametric Equations, and Polar Coordinates. Copyright Cengage Learning. All rights reserved. 10 Conics, Parametric Equations, and Polar Coordinates Copyright Cengage Learning. All rights reserved. 10.5 Area and Arc Length in Polar Coordinates Copyright Cengage Learning. All rights reserved. Objectives

More information

Review for Applications of Definite Integrals Sections

Review for Applications of Definite Integrals Sections Review for Applications of Definite Integrals Sections 6.1 6.4 Math 166 Iowa State University http://orion.math.iastate.edu/dstolee/teaching/15-166/ September 4, 2015 1. What type of problem: Volume? Arc

More information

while its direction is given by the right hand rule: point fingers of the right hand in a 1 a 2 a 3 b 1 b 2 b 3 A B = det i j k

while its direction is given by the right hand rule: point fingers of the right hand in a 1 a 2 a 3 b 1 b 2 b 3 A B = det i j k I.f Tangent Planes and Normal Lines Again we begin by: Recall: (1) Given two vectors A = a 1 i + a 2 j + a 3 k, B = b 1 i + b 2 j + b 3 k then A B is a vector perpendicular to both A and B. Then length

More information

Dr. Allen Back. Nov. 21, 2014

Dr. Allen Back. Nov. 21, 2014 Dr. Allen Back of Nov. 21, 2014 The most important thing you should know (e.g. for exams and homework) is how to setup (and perhaps compute if not too hard) surface integrals, triple integrals, etc. But

More information

Total. Math 2130 Practice Final (Spring 2017) (1) (2) (3) (4) (5) (6) (7) (8)

Total. Math 2130 Practice Final (Spring 2017) (1) (2) (3) (4) (5) (6) (7) (8) Math 130 Practice Final (Spring 017) Before the exam: Do not write anything on this page. Do not open the exam. Turn off your cell phone. Make sure your books, notes, and electronics are not visible during

More information

Math 11 Fall 2016 Section 1 Monday, October 17, 2016

Math 11 Fall 2016 Section 1 Monday, October 17, 2016 Math 11 Fall 16 Section 1 Monday, October 17, 16 First, some important points from the last class: f(x, y, z) dv, the integral (with respect to volume) of f over the three-dimensional region, is a triple

More information

Conics, Parametric Equations, and Polar Coordinates. Copyright Cengage Learning. All rights reserved.

Conics, Parametric Equations, and Polar Coordinates. Copyright Cengage Learning. All rights reserved. 10 Conics, Parametric Equations, and Polar Coordinates Copyright Cengage Learning. All rights reserved. 10.5 Area and Arc Length in Polar Coordinates Copyright Cengage Learning. All rights reserved. Objectives

More information

Midterm Review II Math , Fall 2018

Midterm Review II Math , Fall 2018 Midterm Review II Math 2433-3, Fall 218 The test will cover section 12.5 of chapter 12 and section 13.1-13.3 of chapter 13. Examples in class, quizzes and homework problems are the best practice for the

More information

Geometric transformations assign a point to a point, so it is a point valued function of points. Geometric transformation may destroy the equation

Geometric transformations assign a point to a point, so it is a point valued function of points. Geometric transformation may destroy the equation Geometric transformations assign a point to a point, so it is a point valued function of points. Geometric transformation may destroy the equation and the type of an object. Even simple scaling turns a

More information

Math Exam III Review

Math Exam III Review Math 213 - Exam III Review Peter A. Perry University of Kentucky April 10, 2019 Homework Exam III is tonight at 5 PM Exam III will cover 15.1 15.3, 15.6 15.9, 16.1 16.2, and identifying conservative vector

More information

1.5 Equations of Lines and Planes in 3-D

1.5 Equations of Lines and Planes in 3-D 1.5. EQUATIONS OF LINES AND PLANES IN 3-D 55 Figure 1.16: Line through P 0 parallel to v 1.5 Equations of Lines and Planes in 3-D Recall that given a point P = (a, b, c), one can draw a vector from the

More information

Unit 12 Topics in Analytic Geometry - Classwork

Unit 12 Topics in Analytic Geometry - Classwork Unit 1 Topics in Analytic Geometry - Classwork Back in Unit 7, we delved into the algebra and geometry of lines. We showed that lines can be written in several forms: a) the general form: Ax + By + C =

More information

14.4: Tangent Planes and Linear Approximations

14.4: Tangent Planes and Linear Approximations 14.4: Tangent Planes and Linear Approximations Marius Ionescu October 15, 2012 Marius Ionescu () 14.4: Tangent Planes and Linear Approximations October 15, 2012 1 / 13 Tangent Planes Marius Ionescu ()

More information

Introduction to Transformations. In Geometry

Introduction to Transformations. In Geometry + Introduction to Transformations In Geometry + What is a transformation? A transformation is a copy of a geometric figure, where the copy holds certain properties. Example: copy/paste a picture on your

More information

Differentiability and Tangent Planes October 2013

Differentiability and Tangent Planes October 2013 Differentiability and Tangent Planes 14.4 04 October 2013 Differentiability in one variable. Recall for a function of one variable, f is differentiable at a f (a + h) f (a) lim exists and = f (a) h 0 h

More information

Let s write this out as an explicit equation. Suppose that the point P 0 = (x 0, y 0, z 0 ), P = (x, y, z) and n = (A, B, C).

Let s write this out as an explicit equation. Suppose that the point P 0 = (x 0, y 0, z 0 ), P = (x, y, z) and n = (A, B, C). 4. Planes and distances How do we represent a plane Π in R 3? In fact the best way to specify a plane is to give a normal vector n to the plane and a point P 0 on the plane. Then if we are given any point

More information

1. Suppose that the equation F (x, y, z) = 0 implicitly defines each of the three variables x, y, and z as functions of the other two:

1. Suppose that the equation F (x, y, z) = 0 implicitly defines each of the three variables x, y, and z as functions of the other two: Final Solutions. Suppose that the equation F (x, y, z) implicitly defines each of the three variables x, y, and z as functions of the other two: z f(x, y), y g(x, z), x h(y, z). If F is differentiable

More information

Coordinate Transformations in Advanced Calculus

Coordinate Transformations in Advanced Calculus Coordinate Transformations in Advanced Calculus by Sacha Nandlall T.A. for MATH 264, McGill University Email: sacha.nandlall@mail.mcgill.ca Website: http://www.resanova.com/teaching/calculus/ Fall 2006,

More information

Lines and Planes in 3D

Lines and Planes in 3D Lines and Planes in 3D Philippe B. Laval KSU January 28, 2013 Philippe B. Laval (KSU) Lines and Planes in 3D January 28, 2013 1 / 20 Introduction Recall that given a point P = (a, b, c), one can draw a

More information

Solution 2. ((3)(1) (2)(1), (4 3), (4)(2) (3)(3)) = (1, 1, 1) D u (f) = (6x + 2yz, 2y + 2xz, 2xy) (0,1,1) = = 4 14

Solution 2. ((3)(1) (2)(1), (4 3), (4)(2) (3)(3)) = (1, 1, 1) D u (f) = (6x + 2yz, 2y + 2xz, 2xy) (0,1,1) = = 4 14 Vector and Multivariable Calculus L Marizza A Bailey Practice Trimester Final Exam Name: Problem 1. To prepare for true/false and multiple choice: Compute the following (a) (4, 3) ( 3, 2) Solution 1. (4)(

More information

Multivariable Calculus

Multivariable Calculus Multivariable Calculus Chapter 10 Topics in Analytic Geometry (Optional) 1. Inclination of a line p. 5. Circles p. 4 9. Determining Conic Type p. 13. Angle between lines p. 6. Parabolas p. 5 10. Rotation

More information

A1:Orthogonal Coordinate Systems

A1:Orthogonal Coordinate Systems A1:Orthogonal Coordinate Systems A1.1 General Change of Variables Suppose that we express x and y as a function of two other variables u and by the equations We say that these equations are defining a

More information

Analytic Spherical Geometry:

Analytic Spherical Geometry: Analytic Spherical Geometry: Begin with a sphere of radius R, with center at the origin O. Measuring the length of a segment (arc) on a sphere. Let A and B be any two points on the sphere. We know that

More information

27. Tangent Planes & Approximations

27. Tangent Planes & Approximations 27. Tangent Planes & Approximations If z = f(x, y) is a differentiable surface in R 3 and (x 0, y 0, z 0 ) is a point on this surface, then it is possible to construct a plane passing through this point,

More information

INTRODUCTION TO LINE INTEGRALS

INTRODUCTION TO LINE INTEGRALS INTRODUTION TO LINE INTEGRALS PROF. MIHAEL VANVALKENBURGH Last week we discussed triple integrals. This week we will study a new topic of great importance in mathematics and physics: line integrals. 1.

More information

Differential Geometry: Circle Patterns (Part 1) [Discrete Conformal Mappinngs via Circle Patterns. Kharevych, Springborn and Schröder]

Differential Geometry: Circle Patterns (Part 1) [Discrete Conformal Mappinngs via Circle Patterns. Kharevych, Springborn and Schröder] Differential Geometry: Circle Patterns (Part 1) [Discrete Conformal Mappinngs via Circle Patterns. Kharevych, Springborn and Schröder] Preliminaries Recall: Given a smooth function f:r R, the function

More information

Parametric Surfaces and Surface Area

Parametric Surfaces and Surface Area Parametric Surfaces and Surface Area What to know: 1. Be able to parametrize standard surfaces, like the ones in the handout.. Be able to understand what a parametrized surface looks like (for this class,

More information

The Three Dimensional Coordinate System

The Three Dimensional Coordinate System The Three-Dimensional Coordinate System The Three Dimensional Coordinate System You can construct a three-dimensional coordinate system by passing a z-axis perpendicular to both the x- and y-axes at the

More information

1.5 Equations of Lines and Planes in 3-D

1.5 Equations of Lines and Planes in 3-D 56 CHAPTER 1. VECTORS AND THE GEOMETRY OF SPACE Figure 1.16: Line through P 0 parallel to v 1.5 Equations of Lines and Planes in 3-D Recall that given a point P = (a, b, c), one can draw a vector from

More information

LINEAR ALGEBRA AND VECTOR ANALYSIS MATH 22A

LINEAR ALGEBRA AND VECTOR ANALYSIS MATH 22A 1 2 3 4 Name: 5 6 7 LINEAR ALGEBRA AND VECTOR ANALYSIS 8 9 1 MATH 22A Total : Unit 28: Second Hourly Welcome to the second hourly. Please don t get started yet. We start all together at 9: AM. You can

More information