Question

упростить cos^2α-cos^4α+sin^4α​

Answer 1

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