Answer:
x = -2y^2
Explanation Part 1:
It's not vertical, and thus it's not a standard (y = ax^2 + b) parabola.
This must mean it's either x = 2y^2 or x = -2y^2
Explanation Part 2:
You can test values into either one to check if it works
Take (-2, 1) for example, doesn't have to be a precise coordinate pair:
First Equation
x = 2y^2
-2 = 2(1)^2
-2 = 2(1)
-2 = 2
DOESN'T WORK!
Second Equation
x = -2y^2
-2 = -2(-1)^2
-2 = -2(1)
-2 = -2
IT WORKS!