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. 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) 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

2 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 ) 6) What is the value of using flags in a program? 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; end a=a+2; end z 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

3 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: b. What is the result printed to the command window if the code from part a. is run in the command window? c. What is the result of A + C? d. What is the result of A + B? e. What is the result of A * B? 10) What are two situations a programmer will choose to use a while loop in their code over a for loop? 11) List 3 built in MATLAB functions that have been used throughout the course: 12) Given the matrix M, sum(m) returns a row vector with the sum of each column: TRUE FALSE

4 13) Label the different components of the function definition line below, and what they do: function [A] = hmm(b,c) 14) What will print to the command window when the script and function files are executed below? Script file: L = 5; W = 2; D = 4; Vol = RectVol(L,W,D) Function File (RectVol.m): function output = RectVol(L,W) output = L * W * D; end 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) 16) What are the two main benefits of using user defined functions?

5 ENGR 1181 Exam 2 Application Review MATLAB Application You are being assigned two problems. Complete each problem in a separate script file. Include comment statements to help organize your script file and try to implement flexible coding. Include the standard header. Problem 1 Background Industrial Systems Engineers often take measurements of large data sets to analyze how conditions of a process could be optimized to increase efficiency, reduce cost, or improve customer experience (Lean and Six Sigma!). This could apply to many different areas such as a plant/ factory, store transactions, or supply chain. Problem Statement You are an Industrial Systems Engineer who is looking to improve customer experience in fast food lines. You have created a machine which will accept customers money, and tell them what items they can afford based on the amount they have inputted and then return it to them. All that s left is to write the code for the machine in MATLAB. The menu items that a customer can afford based on the amount inputted are listed below: o Under 2 dollars: A soda or fries o Under 5 dollars: A soda, and fries, or a sandwich o Under 8 dollars: A soda, fries and a sandwich o 8 dollars or over: A soda, fries, a sandwich and a frosty In your script file, prompt the user to enter a dollar amount. Based on this amount tell the user what items they can afford based on the list above. After, ask the user if they would like to add more money to the initial amount. If they say yes, the program should run again with the initial amount + the amount of money added for as many times as they decide to add money. Once the consumer does not want to add anymore, end the program and return their money.

6 Problem 2 Background Chemical Engineers use different methods to extract chemicals of interest after a reaction has occurred. There are many different methods: distillation, absorption, filtration, absorption, etc depending on the value of the chemical and the concentration required by the customer. Problem Statement You are a chemical engineer who is using an adsorption based separation to remove fluoride from water to avoid the local population from attaining fluorosis. To perform further calculations, you need to plot the Langmuir isotherm model given by the equation below: Where and 1/ ranges from 1 to 250. On your own determine a proper step size for your solution. You will be asked to solve this problem using three different approaches, two in MATLAB, and one in Excel. Given that the base equations are the same, all three graphs should be identical. NOTE: 1/Ca ranges from 1 to 250, but the equation calls for Ca. Think of how we can convert our data sets in both MATLAB and Excel to be utilized in the equation above. PART 1 In MATLAB, utilize an array and dot operators to complete the computation obtain the values of for the range of Ca. Then plot the equation of vs.. Remember to follow good graphing practices. PART 2 In MATLAB, utilize a function file and a for loop to calculate all of the values of and store them as an array. The function should only have one input,, and from that calculate one output,. Then plot the equation of vs.. Remember to follow good graphing practices. PART 3 In Excel, generate the values of based on the range of Ca, the given equation, and cell referencing. Then plot the equation of vs.. Remember to follow good graphing practices.