# Simplifying a trig equation

1. Nov 7, 2007

### physstudent1

1. The problem statement, all variables and given/known data
(this is really only part of my problem it's an optimization problem but this is where I'm stuck)
Find the zeros of: cos^2(x)-sin^(x)+cos(x)

2. Relevant equations

3. The attempt at a solution

I've been trying to use trig identities such as sin^2 + cos^2 = 1 but it's not getting me anywhere I know the answer is pi/3 because our teacher told us but I can't seem to get it.

2. Nov 7, 2007

### EnumaElish

I'd try to convert all the terms to cos(x), then set y = cos(x), then use the quadratic formula.

3. Nov 7, 2007

### physstudent1

thanks I got 1/2 and -1 for the roots with that then set that equal to cos(x) to find the roots of the actual problem ?

Last edited: Nov 7, 2007
4. Nov 7, 2007

### rocomath

$$\cos^{2}{x}-\sin{x}+\cos{x}$$

you have sin^x ... idk how to interpret that

5. Nov 8, 2007

### Staff: Mentor

Or is it

$$\cos^{2}{x}-\sin^{2}{x}+\cos{x}$$ ??