If A = [a ij ] is a 3 × 3 scalar matrix such that a 11 = 2, then write the value of |A|.

Question

Philoid · Accepted Answer

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

Hence

Then,

Expanding along R₁

|A|=2(2×2-0)

=8