Question

ДАЮ 20 БАЛЛОВ,ПОМОГИТЕ С ПРИМЕРОМ ПЖ((((((((((

Answer 1

$\frac{4 \sin( \alpha ) \cos( \alpha ) + { \sin^{2}( \alpha ) } }{ \cos^{2}( \alpha ) - \sin^{2}( \alpha ) } = \\ = \frac{ \frac{4 \sin( \alpha ) \cos( \alpha ) + { \sin^{2}( \alpha ) }}{ \cos ^{2} ( \alpha ) } }{ \frac{\cos^{2}( \alpha ) - \sin^{2}( \alpha )}{cos ^{2} ( \alpha )} } = \\ = \frac{4tg \alpha + tg ^{2} \alpha }{1 - {tg}^{2} \alpha } = \\ = \frac{4 \times 2 + {2}^{2} }{1 - {2}^{2} } = \frac{12}{ - 3} = - 4$