Question

Упростите выражение
1) sin(x+y) - cosx * cosy
2) 1-cos2x/sin(π-x)

Answer 1

$\sin(x+y)-\cos x\cos y=\sin x\cos y+\sin y\cos x-\cos x\cos y$

$\frac{1-\cos 2x}{\sin ( \pi -x)} = \frac{1-1+2\sin^2x}{\sin x} =2\sin x$