Question

Exercise 1: Use Matlab command to obtain the following a) Extract the fourth row of the matrix generated by magic(6) b) Show the results of 'x' multiply by 'y' and 'y' divides by 'x'. Given x = [0:0.1:1.1] and y=[10:21] c) Generate random matrix 'r' of size 4 by 5 with number varying between -8 and 9 Exercise 2: Use MATLAB commands to get exactly as the figure shown below x=pi/2:pi/10:2*pi; y=sin(x); z=cos (x);

Answer 1

a) extracting the fourth row of a matrix magic(6) which is a 6*6 square matrix

>>A=magic(6)

>>B=A(4,:)   %This is used to extract the 4th row of the matrix

b)x multiply by y.(multiplying the corresponding element).

x is a 1*12 matrix and y is also a 1*12 matrix .Multiplying the corresponding element will give 1*12 matrix .

>> x.*y
ans =

Columns 1 through 4:

    0.00000    1.10000    2.40000    3.90000

Columns 5 through 8:

    5.60000    7.50000    9.60000   11.90000

Columns 9 through 12:

   14.40000   17.10000   20.00000   23.10000

y divides x .Dividing corresponding values.

>> y./x
ans =

Columns 1 through 8:

       Inf   110.000    60.000    43.333    35.000    30.000    26.667    24.286

Columns 9 through 12:

    22.500    21.111    20.000    19.091

c) Generating random matrix r of size 4 by 5 with number varying between -8 and 9

>>r=randi([-8,9],4,5)

output:

>>

r =

-1 -6 -1 -8 -2
   1   8 -3 -3   4
   0   3 -4   7   8
-6   5 -5   4 -2