Deck 15: Computational Engineering Tools: Matlab

Question 1

If you define x = 2/3, and then type format bank, how will the value of x be displayed?

A)x = 0.66666666667
B)x = 0.6667
C)x = 0.67
D)x = 2/3

Answer 1

C

Question 2

If you define x = 2/3, and then type format long, how will the value of x be displayed?

A)x = 0.66666666666666666666667
B)x = 0.66666666666667
C)x = 0.67000000000000
D)x = 2/3

Answer 2

B

Question 3

To clear the contents of the Command Window, type

A)clear
B)clr
C)clc
D)shift-c

Answer 3

C

Question 4

To generate the set of x even numbers in the range of two to twenty, what should you enter in the Command Window?

A)x = 2;2;20
B)x = 2:2:20
C)x = 2:20:2
D)x = 2,20,2

Question 5

Shown below are MATLAB inputs.Complete each output:
>> E = [10:-2:0];
>> F = 20./E
>> F =

Question 6

Shown below are MATLAB inputs.Complete each output:
>> A = [1:4];
>> B = 3.*A
>> B =

Question 7

In the MATLAB environment, you can assign values to a variable or define the elements of a matrix.

Question 8

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> A(4:8)

Question 9

Shown below are MATLAB inputs.Complete each output:
>> A = [2:5];
>> B = 4*A
>> B =

Question 10

If you define x = 2/3, and then type format rat, how will the value of x be displayed?

A)x = 0.66666666667
B)x = 0.6667
C)x = 0.67
D)x = 2/3

Question 11

If you define x = 2/3, and then type format short, how will the value of x be displayed?

A)x = 0.66666666667
B)x = 0.6667
C)x = 0.67
D)x = 2/3

Question 12

The part of the screen where you enter variables and issue MATLAB commands is known as the

A)menu bar.
B)current folder.
C)command window.
D)command history window.

Question 13

Engineers can use MATLAB to solve a wide range of engineering problems.They take advantage of built-in functions of the software and also they can write their own programs in MATLAB.

Question 14

Shown below are MATLAB inputs.Complete each output:
>> C = [1,3,-2,0];
>> D = 3./C
>> D =

Question 15

In MATLAB, the elements of the matrix are enclosed in brackets [ ] and are separated by blank space, and the elements of each row are separated by a semicolon (;)

Question 16

In MATLAB, you cannot transfer old commands from the Command History Window to the Command Window.

Question 17

Suppose you have defined x = [1,2,3] and y = [2,4,6] in the Command Window.Determine the result of the following MATLAB operation: >>x + y

A)ans = 3 6 9
B)ans = 1 2 3 2 4 6
C)ans = 6 12
D)ans = 18

Question 18

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> B(2:5)

Question 19

Suppose you have defined x = [1,2,3] and y = [2,4,6] in the Command Window.Determine the result of the following MATLAB operation: >>x .* y

A)ans = 3 6 9
B)ans = 1 2 3 2 4 6
B)ans = 2 8 18
C)ans = 6 12

Question 20

Shown below are MATLAB inputs.Complete each output:
>> A = [2:5];
>> B = 4.*A
>> B =

Question 21

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> A(2:3,:)

Question 22

What does the following MATLAB function do? log2(x)

A)returns the value of base-2 logarithm of x.
B)returns the value of base-10 logarithm of 2 and assigns it to x.
C)returns the value of common log of 2x.
D)returns the value of natural logarithm of 2 and assigns it to x.

Question 23

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> length (A)

Question 24

To obtain the coefficients of the second order polynomial that best fits a given set of x and y data, you will type the following sequence of commands:

A)Coefficients = polyfit(2, x,y)
B)Coefficients = polyfit(x,2,y)
C)Coefficients = polyfit(x,y,2)
D)none of the above

Question 25

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> A(:,3)

Question 26

Find the corresponding MATLAB output:
>> factorial(3)
ans =

Question 27

Which of the following commands are commonly used while plotting in MATLAB?

A)plot
B)title
C)grid
D)all of the above

Question 28

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> B(:,3:4)

Question 29

In the MATLAB Command Window, if you type the following commands, what would be the result?
scores = [80 90 50 70 80 60 65 95 70 40];
for i=1:1:10
if scores (i) >60
fprintf('\t %g \t\t\t\t\t PASSING\n', scores (i));
else
fprintf('\t %g \t\t\t\t\t FAILING\n', scores (i))
end
end

Question 30

In the MATLAB Command Window, if you type the following commands, what would be the result?
scores = [80 90 50 70 80 60 65 95 70 40];
for i=1:1:10
if scores (i) <60
fprintf ('\t %g \t\t\t\t\t FAILING\n', scores (i))
end
end

Question 31

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> B(2:3, 2:4)

Question 32

an M-file is used to when you write a program that is more than a few lines long.

Question 33

Which of the following MATLAB commands would calculate the value of ex?

A)e^x
B)exp(x)
C)exp^x
D)exponent(x)

Question 34

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> max(B)

Question 35

What is the MATLAB command for calculating the square root of a number?

A)square_root
B)sqrt
C)sqr
D)sq_rt

Question 36

The following matrices have already been defined in MATLAB: What would be the outputs of the following MATLAB inputs:
>> min(A)

Question 37

Find the corresponding MATLAB output:
>> A = [2,3,4,5;1,-3,-7,4;2,3,2,1];
>> max (A)
ans =

Question 38

What would be the result of the following MATLAB commands?
F1x = sym('x^2-25');
solve(F1x)