Posted by **Anonymous** on Monday, November 2, 2009 at 3:45pm.

Use the Pythagorean Identify to show that the double angle formula for cosine can be written as:

cos2x = 2cos^2x - 1

## Answer This Question

## Related Questions

- advanced functions - Use the Pythagorean identity to show that the double angle ...
- trigonometry - Use a compound angle formula for cosine to show that cos2x = cos^...
- trig or geom - i have to use pythagorean theorem to find the leg-measure of x. ...
- Trigonometry - Need help solving problems using the Trigonometric Identities: ...
- Pre-Calculus - Find all solutions to the equation in the interval [0, 2pi) cos4x...
- trig - Use the double angle formula to verify the identity cotxsin2x=1+cos2x
- Math - Use a double-angle formula to find the exact value of cos2x when sinx = 3...
- trig - A coil of wire rotating in a magnetic field induces a coltage E=20sin((...
- Trig - If sinx = 1/4 Find the exact value of cos2x I used the formula for double...
- Advanced Functions - Determine all solutions in the interval x is all real ...

More Related Questions