Question

: If A=
find a matrix B such that AB = 1,
5 2
Verify that BA=​

Answer 1

Explanation:

Let A=⎛⎝⎜111124135⎞⎠⎟ and D=⎛⎝⎜200030005⎞⎠⎟.

It is found that right-multiplication by D multiplies each column of A by the corresponding diagonal entry of D, whereas left-multiplication by D multiplies each row of A by the corresponding diagonal entry of D.

Construct a 3 x 3 matrix B, not the identity matrix or zero matrix, such that AB=BA.