Question

упростите выражение
cos^2 t - cos2t

Answer 1

$cos(t)^{2} - cos(2t) = cos(t)^{2} - cos(t)^{2} + sin(t)^{2} = sin(t)^{2}$

Answer 2

cos^2 t - cos2t= cos^2 t - cos^2 t+sin^2 t=sin^2 t 
cos 2t=cos^2 t - sin^2 t