©THEBRIGHT EXAM STUDY SOLUTIONS 8/26/2024 11:32 AM
Applied Numerical Methods Midterm 1
Exam Questions And Correct Answers
When writing mathematical expressions involving vectors, it is often necessary to include a
period before multiplication (e.g. .*) when we desire element-by-element multiplication because
(select all that apply): - answer✔✔-the default is matrix multiplication as defined in linear
algebra, not element-by-element multiplication.
-failure to do so may result in an error.
-failure to do so may yield unexpected numerical results
Many built-in functions will accept scalars or vectors as input arguments. In general they operate
element by element when the input is a vector.
T/F - answer✔✔True
Below is a list of operations that may all be included in a single command. Please put these in the
order by which MATLAB evaluates them when executing the command. Note operations on the
same precedence level are executed left to right. Also, the order of operations can be overridden
using parentheses.
-exponentiation (^)
-multiplication and division (* /)
-addition and subtraction (+ -)
-parentheses () - answer✔✔1 - parentheses ()
2 - exponentiation (^)
3 - multiplication and division (* /)
4 - addition and subtraction (+ -)
Where you enter MATLAB commands at the prompt - answer✔✔Command Window
, ©THEBRIGHT EXAM STUDY SOLUTIONS 8/26/2024 11:32 AM
Records all previous commands - answer✔✔Command History
Tracks the values of variables as they are created and/or modified - answer✔✔Workspace
Indicates the folder on the computer where MATLAB is looking for files - answer✔✔Current
Folder
The list below shows a variety of assignment commands. Select the ones that will return errors or
an incorrect/unexpected numerical answer if both x and y are vectors of the same length:
1 - z = atand(y/x);
2 - z = 5*x.^2.*y+3*x.*y.^3
3 - z = 2*x.^2+1/y
4 - z = (x + y)/sqrt(x.^2+y.^2)
5 - z = 10*exp(-5*x).*cos(pi*y-pi/2)
6 - z = 10*cos(pi*x).*sin(pi*y).^2; - answer✔✔1,3,4
You are using MATLAB to find one of the sides of a right triangle. The hypotenuse is 7 and the
known side is 4. Which of the following commands is correct? (More than one option may be
correct. Select all the correct options.)
1 - >>a = 4; c = 7; a^2 + b^2 = c^2
2 - >>a = 4; c = 7; b = sqrt(c^2 - a^2)
3 - >>a = 4; c = 7; b^2 = c^2 - a^2
4 - >>a = 4; c = 7; b = (c^2 - a^2)^0.5
5 - All of the above are correct - answer✔✔2,4
A script m-file is simply a list of MATLAB commands saved to a file. When the script is run,
these commands are executed sequentially using the same workspace as the command window.
True/False - answer✔✔True
Match the MATLAB command with the appropriate verbal explanation of what the command is
doing. All of these commands refer to a vector x = [2 -1 3 1.7 99 8]
z = x([2 5]).^2
Applied Numerical Methods Midterm 1
Exam Questions And Correct Answers
When writing mathematical expressions involving vectors, it is often necessary to include a
period before multiplication (e.g. .*) when we desire element-by-element multiplication because
(select all that apply): - answer✔✔-the default is matrix multiplication as defined in linear
algebra, not element-by-element multiplication.
-failure to do so may result in an error.
-failure to do so may yield unexpected numerical results
Many built-in functions will accept scalars or vectors as input arguments. In general they operate
element by element when the input is a vector.
T/F - answer✔✔True
Below is a list of operations that may all be included in a single command. Please put these in the
order by which MATLAB evaluates them when executing the command. Note operations on the
same precedence level are executed left to right. Also, the order of operations can be overridden
using parentheses.
-exponentiation (^)
-multiplication and division (* /)
-addition and subtraction (+ -)
-parentheses () - answer✔✔1 - parentheses ()
2 - exponentiation (^)
3 - multiplication and division (* /)
4 - addition and subtraction (+ -)
Where you enter MATLAB commands at the prompt - answer✔✔Command Window
, ©THEBRIGHT EXAM STUDY SOLUTIONS 8/26/2024 11:32 AM
Records all previous commands - answer✔✔Command History
Tracks the values of variables as they are created and/or modified - answer✔✔Workspace
Indicates the folder on the computer where MATLAB is looking for files - answer✔✔Current
Folder
The list below shows a variety of assignment commands. Select the ones that will return errors or
an incorrect/unexpected numerical answer if both x and y are vectors of the same length:
1 - z = atand(y/x);
2 - z = 5*x.^2.*y+3*x.*y.^3
3 - z = 2*x.^2+1/y
4 - z = (x + y)/sqrt(x.^2+y.^2)
5 - z = 10*exp(-5*x).*cos(pi*y-pi/2)
6 - z = 10*cos(pi*x).*sin(pi*y).^2; - answer✔✔1,3,4
You are using MATLAB to find one of the sides of a right triangle. The hypotenuse is 7 and the
known side is 4. Which of the following commands is correct? (More than one option may be
correct. Select all the correct options.)
1 - >>a = 4; c = 7; a^2 + b^2 = c^2
2 - >>a = 4; c = 7; b = sqrt(c^2 - a^2)
3 - >>a = 4; c = 7; b^2 = c^2 - a^2
4 - >>a = 4; c = 7; b = (c^2 - a^2)^0.5
5 - All of the above are correct - answer✔✔2,4
A script m-file is simply a list of MATLAB commands saved to a file. When the script is run,
these commands are executed sequentially using the same workspace as the command window.
True/False - answer✔✔True
Match the MATLAB command with the appropriate verbal explanation of what the command is
doing. All of these commands refer to a vector x = [2 -1 3 1.7 99 8]
z = x([2 5]).^2
