### Home > PC > Chapter 12 > Lesson 12.2.2 > Problem 12-51

12-51.

From problem 12-45:*A* = matrix associated with 90º counterclockwise rotation*B* = martix associated with reflecting across the *x*-axis

Multiply *A* and *B* in the opposite order you did in problem 12-45. That is, find *BA*.