Question

A= [ 1 4 0 -1 ] B. = [ 2 m [ 0 _1/2 ] Find m if AB = BA

Answer 1

Answer:

m = -1/139

Step-by-step explanation:

Given

A = [ 140 - 1 ]

B = [ 2m[0_1/2]

m=?

If AB= BA

Solution:

Taking Right Hand Side AB

=[140 -1][2m[0-1/2]

=[139][2m[-1/2]

=[139][ -2m/2]

=[139][-m]

-1/139= m........equ(1)

Taking L.H.S

BA= [2m[0 - 1/2] [ 140-1]

= [ 2m [-1/2] [ 139]

= [-m] [ 139]

1/139 = -m

-1/139 = m ........equ(2)

L.H.S = R.H S

m= -1/139