Question

Find the cofactors of the elements of the matrix

`[(-1, 2),(-3, 4)]`

Answer 1

Given, matrix is `[(-1, 2),(-3, 4)]`

Here a₁₁ = –1; ∴ N₁₁ = 4 and A₁₁ = (–1)¹⁺¹ (4) = 4

a₁₂ = 2; ∴ N₁₂ = –3 and A₁₂ = (–1)¹⁺² (–3) = 3

a₂₁ = –3; ∴ N₂₁ = 2 and A₂₁ = (–1)²⁺¹ (2) = –2

a₂₂ = 4; ∴ N₂₂ = –1 and A₂₂ = (–1)²⁺² (–1) = –1

∴ The required cofactors are 4, 3, –2, –1.