Solve the Problem $s ( t ) = - 2 \cos 3$

Multiple Choice

Solve the problem.
-The position of a weight attached to a spring is $s ( t ) = - 2 \cos 3$ t inches after $t$ seconds. What are the frequency and period of the system?

A) Frequency $= \frac { \pi } { 3 }$ cycles per sec, period $= \frac { 3 } { \pi } \sec$
B) Frequency $= 3$ cycles per sec, period $= \frac { 1 } { 3 } \mathrm { sec }$
C) Frequency $= \frac { 3 } { 2 \pi }$ cycles per sec, period $= \frac { 2 \pi } { 3 } \mathrm { sec }$
D) Frequency $= \frac { 3 } { \pi }$ cycles per sec, period $= \frac { \pi } { 3 } \mathrm { sec }$