Question

Evaluate the determinant by using diaganals

Answer 1

C. 26

Explanation:

The question is on finding determinant of 3×3 matrix

General formulae is given by

if we have matrix (a b c)

(d e f)

(g h i ) then the determinant will be given by

a× D( e f) - b × D (d f) + c× D ( d e)

(h i) (g i) (g h)

where D is the determinant

Evaluate

(a b c) (-4 3 3)

(d e f) = (3 0 2) = -4 ×D(0 2) - 3×D (3 2) + 3×D (3 0)

(g h i ) (3 1 1) (1 1) (3 1) (3 1)

= -4 × {(I×0)-(1×2)} -3 {(3×1)-(3×2)} + 3 { (1×3)-(3×0)}

= -4 ×{-2} - 3×{-3} +3× {3}

=8+9+9= 26