Parabola

There are two types of parabolas. A parabola with (x-h)^2=4c(y-k)  form and a parabola with (y-k)^2=4c(x-h). The first parabola has a vertex of (h,k), focus of (h, k+c), directrix of y=k-c and axis of symmetry of x=h. The second parabola has a vertex of (h, k), focus of (h+c, k), directrix of x=h-c, and axis of symmetry of y=k. For both graphs the value of c can be greater than or less than zero. You do the y-intercept if your given an equation of (x-h) and you find the x-intercept if you are given an equation of (y-k). The standard form of the equation of a parabola with focus (0, c), directrix y=-c, c>0, and vertex (0, 0).