Question

Упростите выражение 1-sin2a/cos2a

Answer 1

$\displaystyle \frac{1-\sin2\alpha}{\cos2\alpha} =\frac{(\cos\alpha-\sin\alpha)^2}{\cos^2\alpha-\sin^2\alpha}=\frac{(\cos\alpha-\sin\alpha)^2}{(\cos\alpha-\sin\alpha)(\cos\alpha+\sin\alpha)} =\frac{\cos\alpha-\sin\alpha}{\cos\alpha+\sin\alpha}$