Write the function in terms of its cofunction. Assume that any angle in which an unknown appears is an acute angle.
-$\cos 67.8 ^ { \circ }$
A) $\sin 22.2 ^ { \circ }$
B) $\cos 112.2 ^ { \circ }$
C) $\sec 112.2 ^ { \circ }$
D) $\sin 67.8 ^ { \circ }$

Question

Quizplus · Accepted Answer

The cofunction identity states that $\cos(\theta) = \sin(90^\circ - \theta)$. Therefore, $\cos(67.8^\circ) = \sin(90^\circ - 67.8^\circ) = \sin(22.2^\circ)$.

Write the Function in Terms of Its Cofunction cos⁡67.8∘\cos 67.8 ^ { \circ }cos67.8∘

Write the Function in Terms of Its Cofunction $\cos 67.8 ^ { \circ }$