write the equation of a sine function that has the following characteristics amplitude 9, period 6pi and phase shift -1/4
y=A*sin[B(x+C)] +D
NOTE: the B is outside the bracket
A=amplitude
period is 2pi/B
Phase shift is -C
vertical shift is D
http://www.youtube.com/watch?v=BQ4QzTcG90g
y = 9sin[(1/3)(x +1/4)] = 9sin[(4x + 3)/12]
Here's the graph