I'm trying to relearn some trig for a math placement test to put me into a calculus class and am having trouble with one particular problem. One of the example problems is as follows:(adsbygoogle = window.adsbygoogle || []).push({});

Find cos^2(2x)+sin^2(2x)

I know the trig identity cos^2(x)+sin^2(x)=1 but I don't know how to apply this, if it should be applied at all, to the problem given. Could I get some help?

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# Homework Help: Relearning a little bit of trig

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