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 Question from Sean, a parent: 1/1-cosine(2x) - 1/1+ cos(2x)

Hi Sean,

You didn't give any instructions but I expect you want to simplify

$\frac{1}{1 - \cos(2x)} - \frac{1}{1+\cos(2x}.$

If so I would start with the first fraction and multiply the numerator and denominator by $1+\cos(2x)$ to get

$\frac{1 + \cos(2x)}{(1 - \cos(2x))(1+\cos(2x))} = \frac{1 + \cos(2x)}{1-\cos^2(2x)}.$