Since the directrix is horizontal, use the equation of a parabola that opens left or right.
The vertex is halfway between the directrix and focus. Find the coordinate of the vertex using the formula . The coordinate will be the same as the coordinate of the focus.
Simplify the vertex.
Cancel the common factor of and .
Factor out of .
Factor out of .
Factor out of .
Cancel the common factors.
Factor out of .
Cancel the common factor.
Rewrite the expression.
Divide by .
Subtract from .
The distance from the focus to the vertex and from the vertex to the directrix is . Subtract the coordinate of the vertex from the coordinate of the focus to find .
Subtract from .
Substitute in the known values for the variables into the equation .
Simplify.
Find the Parabola with Focus (2,0) and Directrix x=-2 (2,0) x=-2