Question

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Answer 1

Объяснение:

$\frac{tg(1.5\pi - \alpha )}{tg(\pi - \alpha )} + \frac{1}{ \cos {}^{2} (1.5\pi - \alpha 7) } - 9 = \\ = \frac{ctg \alpha }{ - tg \alpha } + \frac{1}{ {( - \sin( \alpha ) )}^{2} } - 9 = \\ = ctg \alpha \times ( - ctg \alpha ) + \frac{1}{ \sin {}^{2} ( \alpha ) } - 9 = \\ = - {ctg}^{2} \alpha + \frac{1}{ { \sin }^{2} \alpha } - 9 = \\ = - \frac{ \cos {}^{2} ( \alpha ) }{ \sin {}^{2} ( \alpha ) } + \frac{1}{ { \sin}^{2} (\alpha ) } - 9 = \\ = \frac{ \sin {}^{2} ( \alpha ) }{ \sin {}^{2} ( \alpha ) } - 9 = 1 - 9 = - 8$