Friday

December 19, 2014

December 19, 2014

Posted by **Nikki** on Sunday, July 15, 2012 at 5:47pm.

- Trigonometry -
**Damon**, Sunday, July 15, 2012 at 5:49pmhuh?

cos 2 x = cos ( x+x )

= cos x cos x - sin x sin x

= cos^2 x - sin^2 x

**Answer this Question**

**Related Questions**

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

Trigonometry - Identities and proof - Show that cot((x+y)/2) = - (sin x - sin y...

Trigonometry - Verify the identities algebraically. 1.) TAN^5 X= TAN³X SEC²X-TAN...

Math - use the sum and difference identities to find the cosine angle cos pi/9 ...

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

trigonometry - Verify that following are identities: 1. cos 3t = 4 cos³ t-3 cos ...

Trigonometry - Need help solving problems using the Trigonometric Identities: ...

MATH - 1.)Find the exact solution algebriacally, if possible: (PLEASE SHOW ALL ...

trigonometry - Use a compound angle formula for cosine to show that cos2x = cos^...

Trigonometry - Identities - If tan 2x = - 24/7, where 90 degrees < x < 180...