Question

6. If A= 1 2
3 4
and A (adj A)=kI, then the value

of k is​

Answer 1

Answer:

The value of k is -2

Step-by-step explanation:

Given, A=[(1,2),(3,4)]

Adjoint of A=[(4,-2),(-3,1)]

∴ A(adjA)=KI

[(1,2),(3,4)][(4,-2),(-3,1)]=K[(1,0),(0,1)]

[(-2,0),(0,-2)]=[(K,0),(0,K)]

∴ K=−2