Me with this parabola question. it's geometry

The general form of the sideways parabola is x = a(y - k)^2 + h where k is the y coordinate of the vertex, h is the x coordinate of the vertex, a is the multiplier which either shrinks or stretches the parabola about the x axis.  Since we have a point on the graph with coordinates of (-10, 0), we also have an x and a y value to go along with the fact that we have a vertex of (-3, -2).  All we actually need to find is the a value. So let's fill in what we have: -10 = a(0 + 2)^2 - 3 which simplifies to -10 = 4a - 3. Solving for a we get that a = -7/4. So the equation that I get is x = -7/4(y + 2)^2 - 3