Question

tg(a+b)=8, tgb=-3 , то tga=?

Answer 1

$tg(a+b) = \frac{tg(a) + tg(b)}{1-tg(a)*tg(b)}$

$8 = \frac{tg(a)-3}{1+3*tg(a)}$

8+ 24*tg(a) = tg(a)-3 23*tg(a) = -11

tg(a) = -11/23