Sum-to-Product and Product-to-Sum Formulas · Exercise 45

Algebraically determine whether each of the given equation is an identity. If it is not an identity, replace the right-hand side with an expression equivalent to the left side. Verify the results by graphing both expressions on a calculator.

$\frac{cos\left(10\theta \right)+cos\left(6\theta \right)}{cos\left(6\theta \right)-cos\left(10\theta \right)}=cot\left(2\theta \right)cot\left(8\theta \right)$

OpenStax, Algebra and Trigonometry 2e · §9.4 Sum-to-Product and Product-to-Sum Formulas · Exercise 45