Question

упростить неравенство 1-cos2a/sin2a

Answer 1

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