Sin3a , cos3a , tg3a выразите соответсвенно через sina , cosa , tga

[latex]oxed{sin(3a)}=sin(2a+a)=sin(2a)cos(a)+cos(2a)sin(a)=\=2sin(a)*cos(a)*cos(a)+(1-2sin^2(a))sin(a)=\=2sin(a)*(1-sin^2(a))+sin(a)-2sin^3(a)=\=2sin(a)-2sin^3(a)+sin(a)-2sin^3(a)=oxed{3sin(a)-4sin^3(a)}[/latex][latex]oxed{cos(3a)}=cos(2a+a)=cos(2a)*cos(a)-sin(2a)*sin(a)=\=(2cos^2(a)-1)*cos(a)-2sin(a)*cos(a)*sina=\=2cos^3(a)-cos(a)-2cos(a)*(1-cos^2(a))=\=2cos^3(a)-cos(a)-2cos(a)+2cos^3(a)=oxed{4cos^3(a)-3cos(a)}[/latex][latex]oxed{tg(3a)}=tg(2a+a)=frac{tg(2a)+tg(a)}{1-tg(2a)tg(a)}=frac{frac{2tga}{1-tg^2a}+tga}{1-frac{2tga}{1-tg^2a}tga}=frac{2tga+tga(1-tg^2a)}{1-tg^2a-2tg^2a}=\=oxed{frac{3tga-tg^3a}{1-3tg^2a}}[/latex]