posted by Sejul on .
Can you use algebra to find a quadratic equation if your know the coordinates of just ONE point on its graph?
Can you use algebra to find a quadratic equation if your know the coordinates of just TWO points on its graph?
If so, what information is needed?
You mus know 3 coordinats if you want find a quadratic equation.
In general, you need three points, but if you know that one of the points is the vertex, then that gives you extra information. If you know (h,k), then the parabola is
y-k = a(x-h)^2
so only "a" is unknown. The second point will provide that.