Lesson: Equation of a Parabola
In this lesson, we will learn how to find the equation of a parabola using a focus point and a directrix equation or a vertex point and a directrix equation.
Sample Question Videos
Worksheet: 25 Questions • 2 Videos
Find an equation for the parabola whose focus is the point and whose directrix is the line .
Find an expression for the length of the line from to the focus.
Write an expression for the distance between and the directrix .
Equate the two expressions and square both sides.
Expand and simplify the expressions excluding , and then make the subject and simplify.
Write an equation for the parabola whose focus is the point and whose directrix is the line .