Friday

August 1, 2014

August 1, 2014

Posted by **Terri** on Friday, June 29, 2012 at 4:25pm.

- pre cal -
**Steve**, Friday, June 29, 2012 at 4:47pmsin8x = 2sin4xcos4x

= 4sin2xcos2x(cos^2(2x)-sin^2(2x))

= 8sinx*cosx(cos^2(x)-sin^2(x))[(cos^2(x)-sin^2(x)]^2 - 4sin^2(x)cos^2(x)]

and you can expand that in many ways, one of which is, using s=sin(x) c=cos(x):

8sc^7 - 56s^3c^5 + 56s^3c^5 - 8s^7c

**Related Questions**

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

algebra - Can someone please help me do this problem? That would be great! ...

TRIG! - Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6...

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

Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...

trig - Reduce the following to the sine or cosine of one angle: (i) sin145*cos75...

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

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

Pre Cal - which of the expressions are identical? a) cos^2x b)(cosx)^2 c) cos (x...

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