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Assignment 1

Started: Jan 23 at 4:23pm

Quiz Instructions

This assignment tests your knowledge of Basic Operations in Matlab. The total number of points for this quiz is 100.

Address short answer grading questions to: Q14-16 :Lingyu ; Q 17: Shaida

Question 1

Which command is used to clear the command window?

clear

clc

home

clrcmd

Question 2

Using the Help System (type "doc" in command window), try to find the answer to the following question. What is the Matlab command that can be used to create a scatter plot?

whos

lsline

scatter

size

Question 3

Using the Help System, try to find the answer to the following question.  What does the Matlab command "floor" do?

Round toward infinity

Round toward negative infinity

Creates a reference line at the bottom of plot

Lists the smallest elements in array

Question 4

The number of elements in a vector generated by [5:0.5:8] is

8

7

6

5

Question 5

In the command window, if we enter

a=24;

a=217;

a

then the output shown by Matlab is:

Undefined function or variable 'a'.

a=24

a=NaN

a=217

Question 6

A correct name for a variable is

1arearec

area rec

area_rec

$arearec

Question 7

An incorrect name for a variable is

cat1

cat_1

cat_cos

1cat

Question 8

The Matlab command that outputs the number of rows and columns of a matrix is

dimensions

length

msize

size

Question 9

When inputting a matrix, each new row is separated by a

:

;

|

,

Question 10

Which statement will generate the matrix as shown below?

[ 1 5 8 3, 6 6 7 1, 0 1 0 8]

[ 1 5 8 3; 6 6 7 1; 0 1 0 8]

( 1 5 8 3; 6 6 7 1; 0 1 0 8)

[ 1 6 0; 5 6 1; 8 7 0; 3 1 8 ]

Question 11

Which command sequence leads to the pictured matrix being printed in the Command Window?

a=[0 8 3;3 5 5]; b=a'; b(1,:)=NaN; [a b]

a=[0 8 3;3 5 5]; b=transpond(a); b(1,:)=[]; [a b]

a=[0 8 3;3 5 5]; b=a'; b(1,:)=[]; [a b]

a=[0 8 3;3 5 5]; b=a'; b=b(2:3,:); [a; b]

Question 12

Which code represents the shown formula?

y = 2*exp(-t/tau)/sqrt(x+1*x-1)

y = 2*exp(-t/tau)/sqrt((x+1)*(x-1))

y = 2(exp(-t/tau)/sqrt((x+1)*(x-1)))

y = 2*e^(-t/tau)/sqrt((x+1)*(x-1))

Question 13

In order to multiply two matrices A and B as A * B (i.e., not using element-by-element multiplication)

the number of columns of A has to be the same as number of rows of B

the number rows of A has to be same as number of columns of B

both matrices need to be square

[B] [A] also needs to be possible

Enter the following matrix in Matlab:

x = [ 6 2 8 7; 3 5 6 0 ]

Please answer the following questions

Question 14

What matlab command do you use to extract the second row? ("extract" here means to reference or retrieve, not delete)

Question 15

What Matlab command do you use to extract the third column?

Question 16

What Matlab command do you use to delete the last column?

Question 17

Explain what happens when you enter x(:) in the command window. What is the colon operator doing in this case?