Use the conversion formula $\cos x = \sin \left( \frac { \pi } { 2 } - x \right)$ to replace the expression $f ( t ) = 5.2 \cos ( 6 \pi t ) + 10$
By a sine function.

A) $f ( t ) = 5.2 \sin \left( \frac { \pi } { 2 } - 6 \pi t \right) + 10$
B) $f ( t ) = 5.2 \sin \left( \frac { \pi - 6 \pi t } { 2 } \right) + 10$
C) $f ( t ) = 5.2 \sin \left( \frac { \pi } { 2 } - 6 t \right) + 10$
D) $f ( t ) = 6 \sin \left( \frac { \pi } { 2 } - 5.2 \pi t \right) + 10$
E) $f ( t ) = 10 \sin \left( \frac { \pi } { 2 } - 6 \pi t \right) + 5.2$

Question

Use the conversion formula $\cos x = \sin \left( \frac { \pi } { 2 } - x \right)$ to replace the expression   $f ( t ) = 5.2 \cos ( 6 \pi t ) + 10$  
By a sine function.
 
A) $f ( t ) = 5.2 \sin \left( \frac { \pi } { 2 } - 6 \pi t \right) + 10$
B) $f ( t ) = 5.2 \sin \left( \frac { \pi - 6 \pi t } { 2 } \right) + 10$
C) $f ( t ) = 5.2 \sin \left( \frac { \pi } { 2 } - 6 t \right) + 10$
D) $f ( t ) = 6 \sin \left( \frac { \pi } { 2 } - 5.2 \pi t \right) + 10$
E) $f ( t ) = 10 \sin \left( \frac { \pi } { 2 } - 6 \pi t \right) + 5.2$

Quizplus · Accepted Answer

Using the conversion formula $\cos x = \sin \left( \frac { \pi } { 2 } - x \right)$, the expression $5.2 \cos ( 6 \pi t )$ can be directly replaced with $5.2 \sin \left( \frac { \pi } { 2 } - 6 \pi t \right)$, maintaining the same coefficients and constants.

Use the Conversion Formula cos⁡x=sin⁡(π2−x)\cos x = \sin \left( \frac { \pi } { 2 } - x \right)cosx=sin(2π​−x)

Use the Conversion Formula $\cos x = \sin \left( \frac { \pi } { 2 } - x \right)$