Solve by using trigonmetric identities to find the exact val

Solve by using trigonmetric identities to find the exact value. Choose correct answer.

sin 10* cos 50* + cos 10* sin 50*

A. sqroot3/3

B. sqroot3/2

C. 1/2

D. 1/6

Solution

sinAcosB+cosAsinB= sin(A+B)

sin 10* cos 50* + cos 10* sin 50*

=sin(10*+50*)

=sin(60*)

=sqroot3/2

B. sqroot3/2