Use the appropriate reciprocal identity to find the function value. Rationalize the denominator if necessary.
-$\cos \theta$, if $\sec \theta = - 3$
A) $- \frac { 1 } { 3 }$
B) $\frac { 1 } { 3 }$
C) $\frac { 1 } { 2 }$
D) $- \frac { 1 } { 2 }$

Question

Quizplus · Accepted Answer

The reciprocal identity for cosine and secant is $\cos \theta = \frac{1}{\sec \theta}$. Given $\sec \theta = -3$, $\cos \theta = \frac{1}{-3} = -\frac{1}{3}$.

Use the Appropriate Reciprocal Identity to Find the Function Value cos⁡θ\cos \thetacosθ

Use the Appropriate Reciprocal Identity to Find the Function Value $\cos \theta$