Friday

April 18, 2014

April 18, 2014

Posted by **Katie** on Monday, March 5, 2012 at 7:12pm.

please help... this is the only one I

didn't understand out of all my homework...

- Trig -
**Steve**, Monday, March 5, 2012 at 11:46pmsin(a+b)sin(a-b)

(sina cosb + cosa sinb)(sinacosb - cosa sinb)

sin^2acos^2b + sinacosasinbcosb - sinacosasinbcosb - cos^2asin^2b)

(1-cos^2a)cos^2b - (1-cos^2b)cos^2a

cos^2b - cos^2acos^2b - cos^2a + cos^2acos^2b

cos^2b - cos^2a

**Related Questions**

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

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

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

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

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

pre-calc help please ! - how do you verify this identity Sin^3βcosβ+...

Precalc - If α, β, and γ are direction angles for a vector in ...

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