[tex] 2-2\sin^2(\theta)=\cos (\theta) [/tex](adsbygoogle = window.adsbygoogle || []).push({});

I need to solve this quadratic trig equation algebraically of the domain 0<=x<=2pi I know how to do that but in order to solve the trig functions have to be the same I'm having a little trouble how do I change the cos into sin? It's not cos^2 so we cant use the pythagorean identity.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: How to solve 2 - 2sin^2(theta) = cos(theta) on the domain [0,2pi]

**Physics Forums | Science Articles, Homework Help, Discussion**