Simplify .
Answer: (or if is a complex cube root of unity)
Step-by-step solution
Step 1: Factor the denominator
We recognize that the denominator is a difference of two squares. Using the algebraic identity with and , we can factor it into .
Step 2: Cancel common factors
Substituting the factored expression into the denominator, we see the common factor in both the numerator and denominator. Since , we can cancel to obtain .
Step 3: Apply cube root of unity properties
When represents a complex cube root of unity, it satisfies the fundamental relation . From this identity, we can express as .
Step 4: Simplify using
Substituting gives . Multiplying the numerator and denominator by , and using the fact that , we get .