Question

if f(x)= sin2x+cosx, what is f(pi/4)

Answer 1

that is the answer but i don't know how.

Answer 2

it is simple:
\[f\left( {\frac{\pi }{4}} \right) = \sin \left( {2 \cdot \frac{\pi }{4}} \right) + \cos \left( {\frac{\pi }{4}} \right) = ...?\]

Answer 3

oh wow thanks!