Any ideas on how to find the equation for this trig graphs I

Any ideas on how to find the equation for this trig graphs

Identify a Trigonometric equation from its graph Gang, after experimenting with the sliders to see how the values of A,B,C, and D affect the sine and cosine graph, complete a few problems on this accompanying worksheet. c 1.96 Generate New Wave b 0.39 Sine Function Modeling Cosine Function Modeling 1.5,7.25) 12,1) 7.5,-5 25)

Solution

1) amplitude = 7.25 + 5.25 / 2

a = 6.25

vertical shift d = 1

period = 18

2pi / B = 18

B = 2pi / 18 = pi/9

C = pi/6

hence, the function is

Y = 6.25 cos ( pi/9 x +pi/6 ) + 1