Which of the following is a reciprocal identity?

MATHEMATICS · Single correct · AP · AP Precalculus · Trigonometric and Polar Functions · Trigonometric and Polar Functions

Problem

Which of the following is a reciprocal identity? (a)

\tan\theta = \dfrac{\sin\theta}{\cos\theta}

(b)

\cot\theta = \dfrac{\cos\theta}{\sin\theta}

(c)

\sec\theta = \dfrac{1}{\cos\theta}

(d)

\sec\theta = \dfrac{1}{\sin\theta}