Answer:
y=4sin(2x) - 3
Step-by-step explanation:
Recall the form of a sinusoidal function is Asin(Bx + C) + D, where A is the amplitude, B is the frequency (could also be viewed as the period), C is the horizontal (phase) shift, and D is the vertical shift. Also, recall sin(x) has a period of 2π.
You start with the parent function (sin(x)).
Then, knowing the amplitude is 4: 4sin(Bx + C) + D
Then, knowing the period of the regular sine function is 2π, to get to a period of π, divide by 2 (the period of the curve changes by a factor of 1/2), so your B coefficient is 2: 4sin(2x + C) + D
There is no phase shift, so omit C: 4sin(2x) + D
Since the midline is y = -3, that is your vertical shift (D): 4sin(2x) - 3
Graph of y = 4sin(2x) - 3 is below: