Answer to Question #342843 in Linear Algebra for Vnchikuka

Question

Solve for the determinant in the equation below. (10)

 

 1.7.1. 

4 −3 2

1 2 −2

2 −1 −4

 1.7.2

2 −2 1

2 2 1

4 1 3

Answer 1

1.7.1.

Let's solve for the determinant:

$\begin{vmatrix} 4 & -3 & 2 \\ 1 & 2 & -2 \\ 2 & -1 & -4 \end{vmatrix}$ = 4*2*(-4) + 1*(-1)*2 + (-3)*(-2)*2 - (2*2*2 + (-3)*1*(-4) + (-2)*(-1)*4) = -50

Answer: the determinant is equal to -50.

1.7.2.

Let's solve for the determinant:

$\begin{vmatrix} 2 & -2 & 1 \\ 2 & 2 & 1 \\ 4 & 1 & 3 \end{vmatrix}$ = 2*2*3 + 4*(-2)*1 + 2*1*1 - (4*2*1 + 2*(-2)*3 + 2*1*1) =8

Answer: the determinant is equal to 8.