(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

solve the following equations or inequalties for x in the interval [0,2pi)

2cos^2(x) + 1 = 3cos(2x)

2. Relevant equations

3. The attempt at a solution

My attempt at the problem:

2cosx(cos2x) + 1 = 3cos(2x)

2cosx(cos^2x - sin^2x) + 1 = 3cos(2x)

2cos^3x - 2cosxsin^2x + 1 = 3(1-2sin^2x)

2cos^3x - 2cosxsin^2x + 1 = 3-6sin^2x

2cos^3x - 2cosxsin^2x + 1 - 3 + 6sin^2x = 0

and im getting lost here...

please help,

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# Homework Help: Tring inequality

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