Determine the Equation of the Graph $\frac { 1 } { 3 }$

Multiple Choice

Determine the equation of the graph.
-A weight attached to a spring is pulled down 2 inches below the equilibrium position. Assuming that the period of the system is $\frac { 1 } { 3 }$ sec, what is the frequency of the system?

A) $\frac { 2 \pi } { 3 }$ cycles per sec
B) $\frac { 2 } { 3 \pi }$ cycles per sec
C) 3 cycles per sec
D) 6 cycles per sec