Vertex Equation of an inverse quadratic function.
I'm working on a graphing web tool using JSXGraph, The user should be able to draw different functions. I was able to allow the user to draw quadratic functions by creating the vertex of the function where the user clicks, and then creating another point up-right of the the vertex. Then I construct the function by obtaining a through the vertex equation
I isolate a, which gives
As I have the vertex and another point, I obtain a, and then isolating y
with that, I obtain b and then c.
The problem is I also need to allow the user to draw inverted parabolas, however I can't find a way to obtain the function given the vertex and a point. I believe i would be able to, with the vertex equation of the inverse quadratic, following a similar procedure as the one above, but I'm not even sure if that exists given the dual nature of the inverse quadratic.
So is there a vertex equation for the inverse of a quadratic function that would allow me to accomplish what I did above?