Question

Срочно! Пожалуйста помогите

Answer 1

Используем формулы:

$cos2\alpha=cos^2\alpha-sin^2\alpha\\\\sin2\alpha=2sin\alpha*cos\alpha$

Решение.

$\frac{1-cos2\alpha+sin2\alpha}{1+cos2\alpha+sin2\alpha}=tg\alpha\\\\\frac{1-(cos^2\alpha-sin^2\alpha)+2sin\alpha*cos\alpha}{1+(cos^2\alpha-sin^2\alpha)+2sin\alpha*cos\alpha}=tg\alpha\\\\\frac{(1-cos^2\alpha)+sin^2\alpha+2sin\alpha*cos\alpha)}{(1-sin^2\alpha)+cos^2\alpha +2sin\alpha*cos\alpha}=tg\alpha\\\\\frac{sin^2\alpha+sin^2\alpha+2sin\alpha*cos\alpha)}{cos^2\alpha+cos^2\alpha +2sin\alpha*cos\alpha}=tg\alpha$

$\frac{2sin^2\alpha+2sin\alpha*cos\alpha)}{2cos^2\alpha+2sin\alpha*cos\alpha}=tg\alpha\\\\\frac{2sin\alpha*(sin\alpha +cos\alpha)}{2cos\alpha*(cos  \alpha +sin\alpha)}=tg\alpha\\\\\frac{sin\alpha}{cos\alpha}=tg\alpha\\\\tg\alpha=tg\alpha$