Question

ЛЮДИИИИ СРОЧНОООООООООООООООО даю 100 балов​

Answer 1

tg²(540° - a) = tg²(360° + 180° - a) = tg²(180°-a) = tg²a

cos²(630° + a) = cos²(720° - 90° + a) = cos²(-90° + a) = sin²a

$\tg {}^{2} (540 - \alpha ) \times ( \frac{1}{ \cos {}^{2} ( 630 + \alpha )} - 1) = \\ \tg {}^{2} ( \alpha ) \times ( \frac{1}{ \sin {}^{2} ( \alpha ) } - 1) = \\ \tg {}^{2} ( \alpha ) \times \frac{ \sin {}^{2} ( \alpha ) - 1}{ \sin {}^{2} ( \alpha ) } = \\ \tg {}^{2} ( \alpha ) \times \frac{ \cos {}^{2} ( \alpha ) }{ \sin {}^{2} ( \alpha ) } = \\ \tg {}^{2} ( \alpha ) \ctg {}^{2} ( \alpha ) = \\ \frac{ \sin {}^{2} ( \alpha ) }{ \cos {}^{2} ( \alpha ) } \times \frac{ \cos {}^{2} ( \alpha ) }{ \sin {}^{2} ( \alpha ) } = 1$