Question

Упростите: sin^4x-cos^4x+cos^2x

СРОЧНО!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 1

$\sin^4(x)-\cos^4(x)+\cos^2(x)=\\=(\sin^2(x)-\cos^2(x))*(\sin^2(x)+\cos^2(x))+\cos^2(x)=\\=(\sin^2(x)-\cos^2(x))*(1)+\cos^2(x)=\\=\sin^2(x)-\cos^2(x)+\cos^2(x)=\sin^2(x)$