# Trig identity and equation

1. Oct 26, 2008

### zizkio46

1. The problem statement, all variables and given/known data

cos(squared)x = sinx-1/2

2. Relevant equations

cos(squared)x= 1-sin(squared)x

3. The attempt at a solution

I tried everything but my answer does not match my answers in calculator

2. Oct 26, 2008

### jhicks

If $$cos^2(x) = sin(x)-0.5$$ and $$cos^2(x) = 1-sin^2(x)$$, then wouldn't you agree that $$sin(x)-0.5 = 1-sin^2(x)$$? That's a quadratic equation.