An object attached to a coiled spring is pulled down 5 centimeters from its rest position and released. If the motion is simple harmonic in nature, with a period of seconds, answer the following quest

An object attached to a coiled spring is pulled down 5 centimeters from its rest position and released. If the motion is simple harmonic in nature, with a period of seconds, answer the following questions

a. What is the maximum displacement form equilibrium of the object?

=5cm

b. What is the time required for one oscillation?

=pi sec

c. What is the frequency?

=1/pi sec

d. Write an equation to model the motion of the object.

= i need help on this one

I think i got a-c correct but i need help on d