Sdelayte 85 nomer s resheniyem plsss!!!
Sina = b/c; cosa= a/c tgB=b/a; sin2a = 2sinacosa = 2*(b/c)(a/c) sin2a*tgB=2*(b/c)(a/c)*(b/a)=(2b^2*a/c^2*a)=(2b^2/c^2) Ответ: D) 2b^2/c^2
Bolshoye spasibo!!