# How do you write equations as a product of trig functions?

• Nov 13th 2012, 02:03 PM
derek1008
How do you write equations as a product of trig functions?
Write cos3x+cos4x as a product of trigonometric functions?
• Nov 13th 2012, 04:44 PM
skeeter
Re: How do you write equations as a product of trig functions?
Quote:

Originally Posted by derek1008
Write cos3x+cos4x as a product of trigonometric functions?

one of the sum to product identities ...

$\cos{A} + \cos{B} = 2\cos\left(\frac{A+B}{2}\right)\cos\left(\frac{A-B}{2}\right)$