Question

Даю 50 баллов sinα+cos(-α)/1-ctg(-α)=???

Answer 1

$\frac{sin \alpha +cos(- \alpha )}{1-ctg(- \alpha )} = \frac{sin \alpha +cos \alpha }{1+ctg \alpha } = \frac{sin \alpha +cos \alpha }{1+ \frac{cos \alpha }{sin \alpha } }} = \frac{sin \alpha +cos \alpha }{ \frac{sin \alpha +cos \alpha }{sin \alpha } } =sin \alpha$

Answer 2

_________________________