Saturday

December 20, 2014

December 20, 2014

Posted by **Katie** on Monday, March 5, 2012 at 8:23pm.

- Trig -
**john**, Friday, March 9, 2012 at 6:35pmFirst off these are usually not this hard...just saying...ill be changing your alphas to x's and your betas to y's

we will work with the left side because it is easier.

use identity sum and difference

sin(x+y)sin(x+y)=cos^2y-cos^2x

s

- Trig -
**john**, Friday, March 9, 2012 at 6:41pm(sinxcosy+cosxsiny)(sinxcosy-cosxsiny)=

Then, foil those and your middle two terms should cancel out leaving you with

sin^2xcos^2y-cos^2xsin^2y=

now using the pythagereom theorem change all the sin^2's to cos^2 giving you

cos^2y-cos^2xcos^2y-[cos^2xcos^2xcos^2y]=

cos^2y-cos^2xcos^2y-cos^2x+cos^2xcos^2y=

cos^2y-cos^2x

**Answer this Question**

**Related Questions**

Trig - prove sin(α+β)sin(α-β)=cos^2β-cos^2α please...

Math - If α and β are two angles in Quadrant II such that tan α...

Trig - Prove sin(α+β)sin(α-β)=cos^2β-cos^2α

Trig - prove sin(α+β)sin(α-β)=cos^2β-cos^2α

Trig - prove sin(α+β)sin(α-β)=cos^2β-cos^2α

math - Complex numbers α and β satisfy αα¯=ββ¯=&#...

Pure Mathematics - 4) The roots of the equation z^2+2z+4=0 are denoted by α...

MATH - Differential equations, initial value problem. The general equation of ...

PHYSICS - This is the same question as last time. "A plane is flying 25 degrees ...

physics (speed of plane by radar) - The radar stations A and B, separated by the...