Using both the rotation matrices earlier in this lesson and your matrix calculator, find each determinant. det −1 0 0 −1 = det 0 1 −1 0 = find the following determinant by hand. det 1 2 2 − 2 1 2 = in mathematics, a pattern may suggest a conclusion, but it is not proof of it. next you will prove that the determinant of a rotation matrix (ccw about the origin) must be 1. luckily, there is the general rotation matrix you can use. det cosx −sinx sinx cosx =