Question

1-2sin^2a/-1+2cos^2a упростить выражение.

Answer 1

1- 2 sin^2 a = sin^2 a + cos^2 a - 2 sin^2 a =cos^2 a - sin^2 a ;
-1 + 2 cos^2 a = - sin^2 a - cos^2 a + 2 cos^2 a = cos^2 a - sin^2 a;
  (1 - 2 sin^2 a) /  - 1 + 2 cos^2 a) = 1