- #1

- 29

- 0

## Homework Statement

Solve each equation for [tex]0≤\Theta≤2\pi[/tex] (exact values where possible)

The question:

[tex]2cos^22\Theta - cos2\Theta - 1=0 [/tex]

## Homework Equations

[tex]cos2\Theta = 2cos^2\Theta-1[/tex]

## The Attempt at a Solution

[tex]2cos^22\Theta - 2cos^2\Theta - 1 - 1 = 0[/tex]

[tex]2cos^22\Theta - 2cos^2\Theta - 2 = 0[/tex]

[tex]2(cos^22\Theta - cos^2\Theta - 1)=0[/tex]

I have absolutely no idea what to do after this.

**4. Answer to the question**

[tex]0,\frac{\pi}{3}, \frac{2\pi}{3}, \pi, \frac{4\pi}{3}, \frac{5\pi}{3}, 2\pi[/tex]

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