Question

establish the identity. tan u cot u - sin²u = cos²u. rewrite the factor cot u in the first term, tan u cot u, in terms of tan u. tan u·1/tan u - sin²u. simplify the expression from the previous step by canceling the common factor. 1 - sin²u. the expression from the previous step is equivalent to cos²u using what? a. cancellation property b. even - odd identity c. quotient identity d. pythagorean identity e. reciprocal identity

Explanation:

The Pythagorean identity in trigonometry states that $\sin^{2}u+\cos^{2}u = 1$, which can be rewritten as $1-\sin^{2}u=\cos^{2}u$.

Answer:

D. Pythagorean Identity