Question

I'm not sure if this is right or not could someone also explain why ?

Answer 1

The mapping rule for 90 degrees counterclockwise would be (-y,x). So if you had (x,y) it would transfer to (-y,x). Yours is wrong it should be (4,-3). Remember
-(-4) is 4 and -3 stays as -3.

Basically, memorize these mapping rules.

Hope this helped!