Use the given function value(s), and trigonometric identities (including the cofunction identities), to find the indicated trigonometric functions.
$\sec \theta = 9$
Cos $\theta$

A) $\cos \theta = 9$
B) $\cos \theta = \frac { 1 } { 9 }$
C) $\cos \theta = - \frac { 1 } { 9 }$
D) $\cos \theta = - 9$
E) $\cos \theta = 0$

Question

Use the given function value(s), and trigonometric identities (including the cofunction identities), to find the indicated trigonometric functions. 
 $\sec \theta = 9$  
Cos $\theta$
 
A) $\cos \theta = 9$
B)  $\cos \theta = \frac { 1 } { 9 }$
C)  $\cos \theta = - \frac { 1 } { 9 }$
D)  $\cos \theta = - 9$
E)  $\cos \theta = 0$

Quizplus · Accepted Answer

The secant function is the reciprocal of the cosine function, so if $\sec \theta = 9$, then $\cos \theta = \frac{1}{\sec \theta} = \frac{1}{9}$.

Use the Given Function Value(s), and Trigonometric Identities (Including the Cofunction