1) As a logical statement, is 1 considered true or false in MATLAB? Explain your answer.

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1 ENGR 1181 Midterm 2+ Review Note: This practice material does not contain actual test questions or represent the format of the final. The first 20 questions should be completed WITHOUT using MATLAB. This review guide only covers content introduced after Midterm 2. The final will be cumulative, so study past material and review worksheets for questions over those sections. 1) As a logical statement, is 1 considered true or false in MATLAB? Explain your answer. It is considered true. In MATLAB, any non zero integer is considered true. 2) What relationship operator for less than or equal to in MATLAB? <= 3) Consider the following code: B = (3==5) + (3<7) * 3 + (2~=89); fprintf( %2.1f \n, B) What value of B will be displayed to the command window? To how many decimal places? 4.0 4) Simplify the following logical expression. Explicitly write down each simplification step you perform. A = (6<10) - 2 & 5 2*(8>=7)^3 & 2^5-32 A = (1) 2 & 5 2 * (1) & A = -1 & 5 2 & 0 A = 1 0 A = 1 5) What will print to the command window once the code has run? Money = 4 if Money < 0 fprintf( Sorry sir, you do not have enough for a taco \n ) elseif Money < 4 fprintf( You can afford one taco \n ) else fprintf( You can afford two tacos or more \n ) Error: At least one END is missing (as long as students know it yields an error it is correct)

2 6) What is the value of using flags in a program? It can be used to mark or reference a certain state or criteria Can be used to control the flow of the code 7) According the code below, what value of z is displayed to the command window? z=1; a=0; for i = 1:3 for k = 1:2 z=z+1+a; a=a+2; z z = 19 8) Given a scalar a value, S, and an array, V, circle the expressions below that require a dot operator: S + V V / S S ^ V S / V S * V V ^ S 9) Given the following arrays A, B, and C, that are defined in MATLAB s workspace answer the questions: A = [ ] B = [ ] C = [8 2 4] a. Write one line of code that multiplies the elements of vector A by the elements of vector B: A.*B b. What is the result printed to the command window if the code from part a. is run in the command window?

3 ans = [ ] c. What is the result of A + C? Error: matrix dimensions must agree d. What is the result of A + B? ans = [ ] e. What is the result of A * B? Error: inner matrix dimensions must agree 10) What are two situations a programmer will choose to use a while loop in their code over a for loop? Can be used to ask user input/ continue to run a simulation until a user specifies otherwise. Can be used to run a calculation for an undetermined number of times to approximate a specified value. 11) List 3 built in MATLAB functions that have been used throughout the course: max(), sum(), length() 12) Given the matrix M, sum(m) returns a row vector with the sum of each column: TRUE FALSE 13) Label the different components of the function definition line below, and what they do: function [A] = hmm(b,c) Function tells MATLAB the.m file is a function file [A] output variable that the function will return hmm name of function (B, C) the two input variables (separated by a comma) 14) What will print to the command window when the script and function files are executed below? Script file:

4 L = 5; W = 2; D = 4; Vol = RectVol(L,W,D) Function File (RectVol.m): function output = RectVol(L,W) output = L * W * D; Error: one or more input arguments missing (The function file only has two inputs, but calls on three for its calculation) 15) What would be an appropriate.m file name for the following function based on its function definition line below? function power_puff_girls = mixing_tank(sugar,spice,everything_nice) mixing_tank.m 16) What are the two main benefits of using user defined functions? They can improve readability Function files reduce the overall amount of code in a programs main script ENGR 1181 Exam 2 Application Review MATLAB Application Problem 1 Script file: clc clear close all %% Problem 1 Running = 1; %Good practice to initialize variables outside of loop Money = 0; extra = 0; fprintf('~~~~welcome~~~~ \n') Money = input('enter the amount of money you will be sping ($): '); while Running %or Running == 1 if Money < 0

5 fprintf('error, please restart the program and enter a positive value \n' ) elseif Money < 2 fprintf('you can afford: a soda and fries \n') %even if you have $.01 % #designflaw elseif Money < 5 fprintf('you can afford: a soda and fries, or a sandwich \n') elseif Money < 8 fprintf('you can afford: a soda, fries, and a sandwich \n') else fprintf('you can afford a soda, fries, a sandwich and a frosty \n' ) Running=input('Do you want to add more money? Enter 1 for yes, 0 for no: ' ); fprintf(' \n'); if Running == 0 fprintf('~~take your money back, thanks and have a nice day~~ \n' ) else extra = input('please specify amount of added money ($): '); Money = Money + extra; %will remember all deposits added to the machine Problem 2 Script File: clc clear close all format shortg format compact fprintf('final Review Set 1 Prb 2\n') disp(date) fprintf(' part \n') one_over_ca = 1:1:250; Ca = 1./one_over_Ca; % Ca = linspace(1/250,1,100); q0 = ; K = ; q = q0*ca./(k+ca); figure(1) plot(ca,q) title('part 1: Langmuir Isotherm Model') xlabel('ca (Kg A/m^3 water)') ylabel('q (KgA/Kg AA)')

6 fprintf(' part 2 using function file \n') Q = chemfcn(ca); figure(2) plot(ca,q,'--r') title('part 2: Langmuir Isotherm Model') xlabel('ca (Kg A/m^3 water)') ylabel('q (KgA/Kg AA)') Function File: function q = chemfcn(ca) %This function is used to find the value q for the langmuir isotherm model q0 = ; K = ; for k = 1:length(Ca) q(k) = q0*ca(k)/(k+ca(k));

7 Part 3: A B C D E F G H I J Part 3 q0= K= eqn in cell B4 1/Ca Ca q =$B$2*B4/($F$2+B4) q (Kg A/Kg AA) q v.s. Ca Ca (Kg A/m^3 water)

8 A B C