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

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

Write cos3x+cos4x as a product of trigonometric functions?

2. ## Re: How do you write equations as a product of trig functions?

Originally Posted by derek1008
Write cos3x+cos4x as a product of trigonometric functions?
one of the sum to product identities ...

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