Identify the equation as either an identity or not.
--2 cos 10x cos 4x = cos 7x cos 3x
A) Identity
B) Not an identity

Question

Quizplus · Accepted Answer

The equation is not an identity because it does not hold true for all values of x. An identity in trigonometry is an equation that is true for all values within the domain of the variables involved. The given equation does not satisfy this condition, as substituting different values of x into both sides of the equation will not yield equal results in general.

Identify the Equation as Either an Identity or Not