# How to determine the point of intersection of sine and cosine?

## Homework Statement

Im not sure how to start this question: determine the points of intersection between $$y=sin x$$ and $$y=cos 2 x$$ for x between 0 and pi.

## The Attempt at a Solution

First thing that comes to mind is the eqaute the two, but i dont know how that helps me?

dextercioby
Homework Helper

HallsofIvy
thanks ive got it now, but is the only point of intersection in the range at $$\frac{\pi}{2}$$? i suppose i could graph it to be sure...
okay, i was solving incorrectly, they will also both be at $$30^{o}$$. i also assumed i would get a "nice" number. thanks.