Friday

February 27, 2015

February 27, 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)

**Answer this Question**

**Related Questions**

Pre-Calculus - I don't understand,please be clear! Prove that each equation is ...

Pre-Calculus - Prove that each equation is an identity. I tried to do the ...

Math - Prove each identity: a) 1-cos^2x=tan^2xcos^2x b) cos^2x + 2sin^2x-1 = sin...

Math - Calculus - The identity below is significant because it relates 3 ...

tigonometry - expres the following as sums and differences of sines or cosines ...

Pre-Cal - 1) Verify the identity cos^2 B - sin^2 B = 2 cos^2 B -1 I know that ...

math - Prove the identity: cos^4(x)-sin^4(x)=1-2sin^2(x).with explanation im ...

Precal - I do not understand how to do this problem ((sin^3 A + cos^3 A)/(sin A...

Trigonometry - Prove the identity sin(x+y+z)+sin(x+y-z)+sin(x-y+z)+ sin(x-y-z...

pre-cal - Simplify the given expression........? (2sin2x)(cos6x) sin 2x and cos ...