Question

Sin2alpha/1+cos2alpha

Answer 1

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