A=│A│= cos2 - (-sin2)= cos2 + (sin2)= 1 ---------- (I)We know that A-1= adj A= adj A [From I]

Q30 of 98 Page 314

If A=then A^-1=?

│A│= cos² - (-sin²)

= cos² + (sin²)

= 1 ---------- (I)

We know that A^-1= adj A

= adj A [From I]

If A is a square matrix such that │A│≠0 and A² – A + 2I = 0 then A^-1=?

If A=is not invertible then λ=?

The matrix A=is

If A=then A-1=?