Which of the following holds goods for any triangle ABC ?

Options

A. `(cos A)/(a) + (cos B)/(b) + (cos C)/(c ) = (a^(2) + b^(2) + c^(2))/(2abc)`
B. `(sin A)/(a) + (sin B)/(b) + (sin C)/(c ) = (3)/(2R)`
C. `(cos A)/(a) + (cos B)/(b) + (cos C)/(c ) = (2abc)/(a^(2) + b^(2) + c^(2))``
D. `(sin 2A)/(a^(2)) = (sin 2B)/(b^(2)) = (sin 2C)/(c^(2))`

Answer

A, B