Question

tg2a+tga=???????????????????

Answer 1

$a)\; \; tg2a+tga=\frac{2tga}{1-tg^2a}+tga=\frac{2tga+tga-tg^3a}{1-tg^2a}=\frac{3tga-tg^3a}{1-tg^2a}=\frac{tga(3-tg^2a)}{1-tg^2a}$

$b)\; \; tg2a+tga=\frac{sin(2a+a)}{cos2a\cdot cosa}=\frac{sin3a}{cos2a\cdot cosa}$