MATLAB OUTPUT QUESTION a In the command window type xpi2 xpi

MATLAB OUTPUT QUESTION

a) In the command window, type “x=pi^2”, “x=pi*2” and “x=pi*2;”. What do the symbols “^”, “*“ and “;” do?

b) (10 pts) In the command window , type “A=[1 2 3 40]”, “B=[1;2;3;40]” and “C=[1,2,3,40]”. Which of these are the same and what is the difference with the other one? Also type “D=ones(4)” , “B*A”, “D.*(B*A)” and “D./(B*A)”. Explain the operations “.*” and “./” and the function “ones()”

c)(10 pts) In the command window, type “A=[-7:0.5:11]”, “B=[-7:1:11]”, ”C=[-7:11]”. Explain the effect of “:” and the values ”0.5” and “1”. Also, type and explain the functions “C(8)”, “sum(C)”, “length(C)”

Solution

> A=[1 2 3 40]

A =

1 2 3 40

> C=[1 2 3 40]

C =

1 2 3 40

B=[1;2;3;40]

B =

1
2
3
40

A and C are same that is vector notaion or arry, When constructing an array, use a comma to separate elements that belong in the same row:

B is 3 cross 1 matrix. \";\" here semicolom use for change row

D=ones(4)

D =

1 1 1 1
1 1 1 1
1 1 1 1
1 1 1 1

B*A

ans =

1 2 3 40
2 4 6 80
3 6 9 120
40 80 120 1600

D.*(B*A)

ans =

1 2 3 40
2 4 6 80
3 6 9 120
40 80 120 1600

D./(B*A)

ans =

1.0000 0.5000 0.3333 0.0250
0.5000 0.2500 0.1667 0.0125
0.3333 0.1667 0.1111 0.0083
0.0250 0.0125 0.0083 0.0006

.* is Array multiplication operator..   .^ is Array exponentiation operator

ones(n) returns an n-by-n matrix of ones.

A=[-7:0.5:11]

A =

Columns 1 through 15

-7.0000 -6.5000 -6.0000 -5.5000 -5.0000 -4.5000 -4.0000 -3.5000 -3.0000 -2.5000 -2.0000 -1.5000 -1.0000 -0.5000 0

Columns 16 through 30

0.5000 1.0000 1.5000 2.0000 2.5000 3.0000 3.5000 4.0000 4.5000 5.0000 5.5000 6.0000 6.5000 7.0000 7.5000

Columns 31 through 37

8.0000 8.5000 9.0000 9.5000 10.0000 10.5000 11.0000

B=[-7:1:11]

B =

-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11

C=[-7:11]

C =

-7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11

-7:0.5:11 means the length is 0.5 between -7 and nex numnber that means the difference is 0.5

-7:1:11 means length is 1 between -7 and next number that means the difference is 1

C(8)

ans =

0

>> sum(C)

ans =

38

>> length(C)

ans =

19

:	Colon; is generates regularly spaced elements and represents an entire row or column.