Posted by **Zack** on Sunday, May 5, 2013 at 11:16am.

Prove the identity:

cos^4 x + sin^4 x = 1 - (1/2)sin^2 (2x)

## Answer this Question

## Related Questions

- Math - Calculus - The identity below is significant because it relates 3 ...
- TRIG! - Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6...
- Advanced Functions/Trig - Prove the following: sin(x+y)sin(x-y) = cos^2 (y) - ...
- Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...
- Trigonometry - Prove the identity sin(x+y+z)+sin(x+y-z)+sin(x-y+z)+ sin(x-y-z...
- MathsSs triG - Consider sin(x-360)sin(90-x)tan(-x)/cos(90+x) 1.A.SIMPLIFY sin(x-...
- trig - it says to verify the following identity, working only on one side: cotx+...
- trig - Reduce the following to the sine or cosine of one angle: (i) sin145*cos75...
- Calculus - Use a trig identity to combine two functions into one so you can ...
- tigonometry - expres the following as sums and differences of sines or cosines ...