1-cos2a/sina упростить

[latex] \frac{1-cos2 \alpha }{sin \alpha } = \frac{cos^2 \alpha +sin^2 \alpha -(cos^2 \alpha -sin^2 \alpha )}{sin \alpha } = \frac{cos^2 \alpha +sin^2 \alpha -cos^2 \alpha +sin^2 \alpha }{y} = \frac{2sin^2 \alpha }{sin \alpha } [/latex][latex]=2sin \alpha [/latex]

[latex] \frac{1-cos2a}{sina} = \frac{(sin^2a+cos^2a)-(cos^2a-sin^2a)}{sina} =\frac{2sin^2a}{sina}=2sina[/latex]