Question

35 б.плиззз........​

Answer 1

$1) \: ( \frac{cos \alpha }{1 + sin \alpha } + \frac{cos \alpha }{1 - sin \alpha } ) \times sin2 \alpha = \\ = \frac{cos \alpha (1 - sin \alpha + 1 + sin \alpha )}{1 - {sin}^{2} \alpha } \times 2sin \alpha cos \alpha = \\ = \frac{2cos \alpha }{ {cos}^{2} \alpha } \times 2sin \alpha cos \alpha = 4sin \alpha \\ 2) \: \frac{tg(\pi - \alpha )}{cos(\pi + \alpha )} \times \frac{sin( \frac{3\pi}{2} + \alpha )}{ctg( \frac{3\pi}{2} - \alpha ) } = \\ = \frac{ - tg \alpha }{ - cos \alpha } \times \frac{ - cos \alpha }{tg \alpha } = - 1$