Answer:
y = 2sin((π/7)x)
Step-by-step explanation:
The graph goes through (0, 0) and has a range of ±2. This matches a sine function with an amplitude (A) of 2 and a vertical offset (C) of zero.
The half-period is 7, so the value of k is such that 7k = π, or k = π/7.
The desired function is y = 2·sin((π/7)x).
