Question

Find the identical expression for the following:
sin(pi/4 +x) + sin(pi/4-x)

Answer 1

is it sqrt(2)*cosx

Answer 2

how do you get that?

Answer 3

I think so - but don't ask me how ^_^

Answer 4

use sin(a+b)+sin(a-b)=2sina cosb

Answer 5

sin(a+b) = sina cosb + cosa sinb
sin(a-b) = sina cosb - cosa sinb

(sina cosb + cosa sinb)+(sina cosb - cosa sinb)

Answer 6

= 2sina cosb

Answer 7

thank you