Найдите sin2a если tga=-4/3 и пи/2

Question

Найдите sin2a если tga=-4/3 и пи/2

Answer 1

Sin2a=2tga/(1+tg^2a)=2*(-4/3)/(1+(-4/3)^2)=-8/3/(1+16/9)=-8/3/25/9=-24/25

Answer 2

sin2a=2tga/(1+tg^2a)=2*(-4/3)/(1+(-4/3)^2)=-8/3/(1+16/9)=-8/3/25/9=-24/25