Question

The vertices of ABC are A(-3,-4),B(-1,3),C(3,-2). The triangle is rotated 90 degrees counterclockwise. Use the rotation matrix [0 -1][1 0] to find the coordinates of C'

A)(-3,2)
B)(4,-3)
C)(-3,-1)
D)(2,3)
I chose A

[0 -1] x [-3 -1 3][-4 3 -2] =

Answer 1

hard to show matrices on here

│0-1││ 3│ = │2│
│1 0││-2│'''│3│

the process goes as follows: 0x3+(-1)x(-2) = 2 and
1x3 + 0x(-2)=3

I don't understand what you tried to do.