Can I solve this Matrix multiple of question?

Write a matlab program to multiplication of second row and second colomn of A matrix with an entered x value. The result matrix must be assigned B matrix. A=[2 9 -3;1 6 0;-2 7 3]

[Paresh yeole]

Is this what you mean?

B = A(2,2)*x

[Kardelen Demir]

i’m not sure. I write the solution of the problem manuallly not with program. I should write signs and commands??

[Paresh yeole]

What is your desired output?

[Walter Roberson]

The desired output is "Full marks on the exam".

[Kardelen Demir]

This problem is not my exam this is my homework my teacher gave us 4 problems i cant just this problem

[Kardelen Demir]

I should use if, for, ; e,g. Also my english is not very good sorry

[John D'Errico]

Yes, but if we do your homework, then do we get credit for it? Will you tell your teacher that you asked someone to do your homework for you?

[Kardelen Demir]

I wrote here because I could not solve. you don't have to solve it, you don't even have to be on this page right now. our teachers are dealing with more important jobs now We are going through hard times as a world because of the pandemic. my teacher did not return yet

Answer 1

[KSSV]

A = rand(4) ;   % matrix must be square 
x = rand ;      % some value of x 
iwant = A(2,:)*x*A(:,2)

[Kardelen Demir]

this equation error on the program. A=[2 9 -3;1 6 0;-2 7 3]

B = A(2,2)*x

then what can i write on the program?

[Kardelen Demir]

i write A=[2 9 -3;1 6 0;-2 7 3]

X=rand;

B = A(2,2)*x

on program because program dont give me matrix why?

[KSSV]

it will not give matrix...becuase what you multiply are two numbers......you are multiplying two scalars.

[Kardelen Demir]

ok i understand thank u so much i'm grateful

[KSSV]

Thanks is accepting the answer. :)

Answer 2

[Paresh yeole]

If you want to mulitply, the value at A(2,2) with x :

B = A(2,2)*x;

Or else if you want to multiply entire second column and entire second row with x and store the result in B then :

A(:,2) = A(:,2)*x;
A(2,:) = A(2,:)*x;
B = A;

If you want A(2,2) to be multipled by x for just once then divide it after the above two operations

[Kardelen Demir]

A=[2 9 -3;1 6 0;-2 7 3]

B = A(2,2)*x

then what can i write on the program? I cant understand.

[Kardelen Demir]

i write A=[2 9 -3;1 6 0;-2 7 3]

X=rand;

B = A(2,2)*x

on program because program dont give me matrix why?