यदि \(\sin A = \dfrac{4}{5}\) तथा \(\sin B = \dfrac{5}{13}\) है, तो Sin (A + B) = ? A. \(\dfrac{63}{65}\) B. \(\dfrac{16}{65}\) C. \(\dfrac{33}{65}\) D. \(\dfrac{56}{65}\)

उत्तर देखें और व्याख्या

उत्तर: (A) A

व्याख्या

sin A = 4/5 gives cos A = 3/5; sin B = 5/13 gives cos B = 12/13. sin(A + B) = sin A cos B + cos A sin B = 48/65 + 15/65 = 63/65.