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January 28, 2015

January 28, 2015

Posted by **Breanna** on Monday, September 28, 2009 at 4:22pm.

cos^4X - sin^4X = 1-2sin^2X

- Math pre cal -
**Reiny**, Monday, September 28, 2009 at 5:37pmLS = (cos^2x + sin^2x)(cos^2x - sin^2x)

= 1((1-sin^2x) - sin^2x)

= 1 - 2sin^2x

= RS

- Math pre cal -
**MathMate**, Monday, September 28, 2009 at 5:38pmFactorize the left hand side using:

A²-B²=(A+B)(A-B)

or

A^{4}-B^{4}= (A²+B²)(A²-B²)

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