Solving Radian Equation: Amp=2/3, Period=4╥, Shift=╥/2

[lucifer_x]

Homework Statement

Write an equation of a sine function with a amp=(2/3) , Period = 4╥ and a phase shift of ╥/2.

in radians

Homework Equations

The Attempt at a Solution

i got

y = 2/3 cos (2...

 

[berkeman]

Homework Statement

Write an equation of a sine function with a amp=(2/3) , Period = 4╥ and a phase shift of ╥/2.

in radians

Homework Equations

The Attempt at a Solution

i got

y = 2/3 cos (2...

Keep going... (and use the sin function)

 

[lucifer_x]

so would the answer be

y = - 2/3 sin ( 2Θ + π )

and

y = 2/3 sin ( 2Θ + π )

??

 

[berkeman]

so would the answer be

y = - 2/3 sin ( 2Θ + π )

and

y = 2/3 sin ( 2Θ + π )

??

I don't think so. How is the period of these functions defined? How is the phase shift defined?