I keep getting wrong answer, Please help! Thank you so much!

Question

A spring oscillates with a frequency of 4 cycles per second. Its initial displacement is 13 centimeters and it's damping factor is 0.65. Give the function,  that describes the position of the spring  seconds after it starts oscillating.

Answer 1

Here is how I would interpret this problem. The starting position is at -13. the spring is then released and rises (.65 x13=8.45) It then returns to starting position and dips 8.45 below start and then returns start position. So midline is at -13 which is vertical shift (d) Amplitude is 8.45(a) There is no phase shift(c)

If frequency is 4 cps then period is .25 sec B=2pi/.25 so b=8pi

Equation is y= a(sinb(t-c) +d

y= 8.45 sin8pi(t) -13