Question

Тригонометрия:
$frac{1+2sinacosa }{sin^2a-cos^2a}= frac{tga+1}{tga-1}$

Answer 1

$frac{1+2sinacdot cosa}{sin^2a-cos^2a} =frac{sin^2a+cos^2a+2sinacdot cosa}{(sina-cosa)(sina+cosa)} =frac{(sina+cosa)^2}{(sina-cosa)(sina+cosa)}=\\= frac{sina+cosa}{sina-cosa} = [; frac{:, cosane 0}{:, cosane 0}; ]= frac{tga+1}{tga-1}$