need you help please please

>> A=[1 2;3 4]; >> B=[9 8 7;6 5 4;3 2 1]; >> a=[11,12] >> b=[21;22]; >> c=[19 18 17]; >> d=[29;28;27];

i am stuck on these questions , i did the rest but really stuck on these question , i spend almost 4 hours playing around with different ways, but can't get the right answer. any help will be much appreciated. Thank you soo much

Answer 1

[Mischa Kim]

John, for the first one, use

 ans1 = [a b'; d B]

it's simply putting together vectors and matrices in the correct order. To get the 1's in the second example, you could use A(1,1), four times. And so on and so forth...

[john hollywood]

thank you soo much it works , what about part F and G '

[Mischa Kim]

F works just the same: put together vectors in the correct order. With the prime (') you can turn a column into a row vector, and vice versa.

G: I already showed you how to get 1's. The zero matrix (2-by-2) you get by using A-A .

[john hollywood]

for 'part F' i just don't how put number "29" in there. also for 'Part G', i just don't know how to put matrix A in that diagonal form.i did try switch rows and columns and also tried transpos but nothing seems to work. i used diag(diag(A')) But its not working. Thank you soo much

[Mischa Kim]

Here you go:

F = [[A(1,1) A(1,1); A(1,1) A(1,1)] a' b; c d(1)]
G = [A(1,1)           A(1,1)-A(1,1) A(1,1)        A(1,1)-A(1,1);
     A(1,1)-A(1,1)  2*A(1,1)        A(1,1)-A(1,1) A(1,1);
     [A(1,1) A(1,1);  A(1,1) A(1,1)]              A-A]

Please post follow-up question and comments as comment, not answers.

[Walter Roberson]

The "2*" of "2*A(1,1)" violates the constraint of not introducing any new scalars. You could replace the "2*A(1,1)" with A(1,1)+A(1,1)

However, as I read the question, the indices (1,1) would be introduced scalars. Forming the 2 x 2 sub-block of 1's then becomes difficult.

[Sagar Damle]

I think we are allowed to use scalars as indices but not as extra data.

John,where did you get these questions(from which book)?If they are in a book,are they in 'Exercise' of a chapter?What are the contents of that chapter?(This will help us to narrow our thinking,because exercise of a chapter contains problems related to that chapter.)

Can we use rem(input_matrix,2) to get output in terms of 0's and 1's only?

Answer 2

[john hollywood]

for 'part F' i just don't how put number "29" in there. also for 'Part G', i just don't know how to put matrix A in that diagonal form.i did try switch rows and columns and also tried transpos but nothing seems to work. i used diag(diag(A')) But its not working. Thank you soo much