YouTube on MSN: How to find vertex, focus and directrix of a horizontal parabola in standard form
How to find vertex, focus and directrix of a horizontal parabola in standard form
MSN: Learn how to find the equation of a parabola given focus and vertex conic sections
Learn how to find the equation of a parabola given focus and vertex conic sections
One description of a parabola involves a point (the focus) and a line (the directrix). The focus does not lie on the directrix. The parabola is the locus of points in that plane that are equidistant from the directrix and the focus.
A parabola is a curve where any point is at an equal distance from: Get a piece of paper, draw a straight line on it, then make a big dot for the focus (not on the line!). Now play around with some measurements until you have another dot that is exactly the same distance from the focus and the straight line.
Like the ellipse and hyperbola, the parabola can also be defined by a set of points in the coordinate plane. A parabola is the set of all points (x, y) in a plane that are the same distance from a fixed line, called the directrix, and a fixed point (the focus) not on the directrix.
MSN: How to find the find the focus and directrix from a sideways parabola with fractions
How to find the find the focus and directrix from a sideways parabola with fractions