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View Full Version : Still don't get it : use tri identities to simplify

dejalisco5
May 14, 2008, 11:20 AM
cos^2 x - sin^2 x/ cos^4 x - sin^4 x
galactus
May 14, 2008, 12:46 PM
Do as I said before. Difference of two squares.

\frac{cos^{2}(x)-sin^{2}(x)}{(cos^{2}(x)+sin^{2}(x))(cos^{2}(x)-sin^{2}(x))}

Now, see it? What does cos^{2}(x)+sin^{2}(x) equal?