A sine function has the following key features:
Period = 4
Amplitude = 4
Midline: y = 1
y-intercept: (0, 1)
The function is not a reflection of its parent function over the x-axis.
Similar to the others, here is the graph:
We have the form
y = Asin (Bx + C) + D
A = the amplitude = 4
To compute "B" we have
B = 2pi / period = 2 pi / 4 = pi /2
C = phase shift (none) so C = 0
D = midline = 1
So.......we have
y = 4 sin ( pi/2 * x ) + 1