The Displacement from Equilibrium of an Object in Harmonic Motion $y = \frac { 1 } { 4 } \cos 8 t - \frac { 1 } { 3 } \sin 15 t$

The displacement from equilibrium of an object in harmonic motion on the end of a spring is $y = \frac { 1 } { 4 } \cos 8 t - \frac { 1 } { 3 } \sin 15 t$ where $y$ is measured in feet and $t$ is the time in seconds. Determine the position of the object when $t = \pi / 12$ . Round your answer to two decimal places.

A) $0.12$ feet
B) $0.21$ feet
C) $17.53$ feet
D) $0.46$ feet
E) $0.11$ feet