Uzasadnij tożsamość: 1 - 2sin^2a * cos^2a = sin^4a + cos^4a a=alfa

1 - 2sin^2a * cos^2a = sin^4a + cos^4a 1 - 2sin^2a * cos^2a = (sin^2a + cos^2a)^2 - 2 sin^2acos^2a 1 - 2sin^2a * cos^2a = 1^2 - 2 sin^2acos^2a 1 - 2sin^2a * cos^2a = 1  - 2 sin^2acos^2a                      L         =          P