Question

2 номер. Нужно решение а не просто ответ.

Answer 1

$frac{1+cos(2alpha+frac{7pi}{2})+sin(2alpha+frac{9pi}{2})}{1-cos(2alpha-frac{7pi}{2})+sin(2 alpha+frac{7pi}{2})}= frac{1+cos(2alpha+frac{3pi}{2})+sin(2 alpha+frac{pi}{2})}{1-cos(2alpha-frac{3pi}{2})+sin(2 alpha+frac{3pi}{2})}= frac{1+sin2alpha+cos2alpha}{1+sin2alpha-cos2alpha} =$
$= frac{sin^2alpha+cos^2alpha+2sinalpha cosalpha+cos^2alpha-sin^2alpha}{sin^2alpha+cos^2 alpha+2sinalpha cosalpha-cos^2alpha+sin^2alpha}= frac{2cos^2alpha+2sinalpha cosalpha}{2sin^2alpha+2sinalpha cosalpha}=$
$=frac{cosalpha(cosalpha+sinalpha)}{sinalpha(sinalpha+cosalpha)}= frac{cosalpha}{sinalpha}=ctg alpha$