Respuesta :

bcalle
The a in front of Sin is the amplitude and the period is 2pi/k.
To get a period of 3pi, set up an equation. 3pi = 2pi/k and solve for k.
3pi = 2pi/k
Multiply k on both sides.
k * 3pi = 2pi
Divide both sides by 3pi
k = 2pi/3pi; k = 2/3

y = 9Sin(2/3)x