Question

If A = [a_ij] is a 3 × 3 scalar matrix such that a₁₁ = 2, then write the value of |A|.

Answer 1

A scalar matrix is a matrix of order m which is equal to a constant λ multiplied with the Identity matrix of order m.

Since a₁₁ = 2, hence λ = 2 and m = 3

Expanding along R₁

|A| = 2(2 × 2 - 0)

= 8