Determine the Equation of the Graph $\frac { 7 } { \pi }$

Multiple Choice

Determine the equation of the graph.
-A weight attached to a spring is pulled down 3 inches below the equilibrium position. Assuming that the frequency of the system is $\frac { 7 } { \pi }$ cycles per second, determine a trigonometric model that gives the position of the weight at time $t$ seconds.

A) $s ( t ) = 3 \pi \cos 7 t$
B) $s ( t ) = - 3 \cos \frac { 7 } { \pi } t$
C) $s ( t ) = 3 \cos 14 t$
D) $s ( t ) = - 3 \cos 14 t$