Упростить tga(1+cos2a)

[latex]analpha(1+cos2 alpha )=analpha(cos^2alpha+sin^2 alpha+cos^2alpha-sin^2 alpha)=[/latex][latex]=analpha*2cos^2alpha=2analpha*cos^2alpha=2 frac{sin alpha cos^2alpha}{cosalpha}= 2sinalpha cosalpha=[/latex][latex]=sin2alpha[/latex]