Question

Cos^4+sin^4 упростить

Answer 1

=$Cos^{4}\alpha+Sin^{4}\alpha=(Cos^{2}\alpha+Sin^{2}\alpha)^{2}-2Sin^{2}\alpha Cos^{2}\alpha=1^{2}-\frac{1}{2}*4Sin^{2}\alpha Cos^{2}\alpha=1-0,5Sin^{2}2\alpha$