How many $y$-intercepts does the graph of the parabola $x = -y^2 + 4y - 4$ have?
You should try graphing it: https://www.desmos.com/calculator/bliuxjinip (answer is 1)
Anyways, this can also be done without graphing.
We first need to know where the parabola is facing. This picture can come in handy:
(If you cant see picture, got to this link: https://www.conceptmathhelp.com/vertex-of-a-paraboladomain-and-range-of-parabola/)
Once you have figured that out, find the vertex using the vertex formula. Since the parabola is opening left, and our vertex has a 0 for the x, it means we have only have 1 y intercept.