Question

помогите tg(2*arctg3)​

Answer 1

${\rm tg}(2{\rm arctg}3)=\dfrac{2{\rm tg}({\rm arctg}3)}{1-{\rm tg}^2({\rm arctg}3)}=\dfrac{2\cdot 3}{1-3^2}=-\dfrac{3}{4}$