Question

Упростите выражение
Cos²x-cos⁴x+sin⁴x

Answer 1

$\cos {}^{2} (x) - \cos {}^{4} (x) + \sin {}^{4} (x) = \cos {}^{2} (x) + \sin {}^{4} (x) - \cos {}^{4} (x) = \cos {}^{2} (x) + ( \sin {}^{2} (x) - \cos {}^{2} (x) )( \sin {}^{2} (x) + \cos {}^{2} (x) ) = \cos {}^{2} (x) + \sin {}^{2} (x) - \cos {}^{2} (x) = \sin {}^{2} (x)$