Question #5df8b

1 Answer
Dec 21, 2016

GIVEN

tan(A+B)tan(AB)=λ

sin(A+B)cos(AB)sin(AB)cos(A+B)=λ

By dividendo and componendo

(sin(A+B)cos(AB))(sin(AB)cos(A+B))(sin(A+B)cos(AB))+(sin(AB)cos(A+B))=λ1λ+1

sin(A+BA+B)sin(A+B+AB)=λ1λ+1

sin(2B)sin(2A)=λ1λ+1

Proved