Write the function in terms of its cofunction. Assume that any angle in which an unknown appears is an acute angle.
-$\tan 69 ^ { \circ }$
A) $\cot 21 ^ { \circ }$
B) $\tan 159 ^ { \circ }$
C) $\cot 69 ^ { \circ }$
D) $\cot 111 ^ { \circ }$

Question

Quizplus · Accepted Answer

The cofunction identity for tangent and cotangent is $\tan \theta = \cot(90^\circ - \theta)$. Therefore, $\tan 69^\circ = \cot(90^\circ - 69^\circ) = \cot 21^\circ$.

Write the Function in Terms of Its Cofunction tan⁡69∘\tan 69 ^ { \circ }tan69∘

Write the Function in Terms of Its Cofunction $\tan 69 ^ { \circ }$