Monday

October 20, 2014

October 20, 2014

Posted by **Carol** on Friday, April 22, 2011 at 1:20pm.

cos(x+y) + cos(x-y)=2cosxcosy

- calculus -
**MathMate**, Friday, April 22, 2011 at 3:08pmcos(a+b)=cos(a)cos(b)-sin(a)sin(b)

cos(a-b)=cos(a)cos(b)+sin(a)sin(b)

What happens when you add the two together?

**Answer this Question**

**Related Questions**

Math - verify the following identity used in calculus: cos(x+h)-cos(x)/h=cos(x)[...

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

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

trig - it says to verify the following identity, working only on one side: cotx+...

calculus - Verify the identity: cos x -cox x/1-tan x = sin x cos x/sin x -cos x

calculus - Verify the identity: cos x -cox x/1-tan x = sin x cos x/sin x -cos x

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

trig - how would you verify this trig identity (1+cos(x) / 1-cos(x)) - (1-cos(x...

Algebra II Part 2 - Use an angle sum identity to verify the identity cos 2 0=2 ...

trig - verify the identity algebraically- (5-5 cos x)(5+5 cos x)=25 (sin^x)