Respuestas

2012-06-07T07:14:50+02:00

cos^2A - sen^2A = 1 - sen^2A
(1 - sen^2A) - sen^2A = 1 - sen^2A
1 - sen^2A - sen^2A = 1 - sen^2A
1 - 2sen^2A = 1 - sen^2A