Question

tg2a-tga спростите срочно!!!спасибо!!

Answer 1

$tg(2a) - tg(a) = \frac{\sin(2a)}{\cos(2a)} - \frac{\sin(a)}{\cos(a)} =$
$= \frac{\sin(2a)\cos(a) - \cos(2a)\sin(a)}{\cos(2a)\cdot \cos(a)} =$
$= \frac{\sin(2a - a)}{\cos(2a)\cos(a)}= \frac{\sin(a)}{\cos(2a)\cos(a)}$