Describe how the graphs of y + 3 = 2sin (3x + 90°) compares to the graph of y = sin (x).

Answer 1

Is my answer correct?
y = 2 sin [3(x + 30)] - 3

amplitude = 2 (compared to 1 for y = sin x)
period = 360 / 3 = 120 (compared to 360 for y = sin x)
phase shift = -30 (compared to 0 for y = sin x)
center of oscillation = -3 (compared to 0 for y = sin x)

the given graph is stretched vertically by 2
shrunk horizontally by a factor of 3 (3 cycles where sin x has 1)
shifted 30 degrees to the left
shifted down 3

Answer 2

perfect.