#1**+1 **

We have the form

y = Asin (Bx) + D

A = the amplitude = 6

B = 2pi / period

The period = 4

So

B = 2pi / 4 = pi/2

D = the shift up/down.....since the resting position is y = 0....we have no shift

The equation for the displacement from the resting position is

y = 6 sin [ (pi/2) t ]

Here is the graph : https://www.desmos.com/calculator/jn8ipp0b2g

CPhill Feb 15, 2019