Question

Can anyone help me solve the following trig question?
Show that
sin(40)+sin(20)=cos(10)

Answer 1

use this identity

\[\sin p+\sin q=2 \sin \frac{p+q}{2} \ \cos \frac{p-q}{2}\]

Answer 2

Hmm I got 2sin(30)cos(10) But I still got the 2 sin(30)

Answer 3

well \(\sin 30=\frac{1}{2}\)

Answer 4

Oh I see I overlooked that thanks.

Answer 5

yw :)