4.11 The inverse and determinant of a matrix

Interactive practice questions

Consider the matrix $A$A$=$=

		$3$3	$4$4
		$5$5	$7$7

Find the determinant of $A$A.

Find the inverse $A^{-1}$A−1.

$A^{-1}$A−1$=$=

		$\editable{}$	$\editable{}$
		$\editable{}$	$\editable{}$

Medium

2min

Consider $A$A$=$=

		$-2$−2	$5$5
		$-1$−1	$2$2

and $B$B$=$=

		$2$2	$-5$−5
		$1$1	$-2$−2

Medium

2min

Consider the matrix $A$A$=$=

		$25$25	$26$26
		$21$21	$22$22

Medium

2min

Consider the matrix $A$A =

		$-7$−7	$-8$−8
		$5$5	$6$6

Medium

2min

Determine the inverse of a 2 × 2 matrix.

Apply the value of the determinant to invertibility and vectors.