Khan Academy: Algebra: Conic Sections: Foci of an Ellipse

The foci of an ellipse are explored in this video. First, foci are shown as the two points on the central axis such that the sum of the distance from a point on the ellipse and the foci points is the same as the distance from any point...

The foci of an ellipse are explored in this video. First, foci are shown as the two points on the central axis such that the sum of the distance from a point on the ellipse and the foci points is the same as the distance from any point...

Sal defines a hyperbola's vertex and foci in this video and shows how to locate both. By comparing the hyperbola to an ellipse throughout the video, the listener sees the similarities between these two conic sections. This approach makes...

In this video, Sal defines the vertex and the foci of a hyperbola, and shows how to locate both. By comparing the hyperbola to an ellipse throughout the video, the listener sees the similarities between these two conic sections. This...

This is the last of three well-done videos on identifying and graphing conic sections from an equation. Here, Sal graphs a circle that is not centered at the origin and a parabola that opens downward.

A video lesson exploring the foci of a hyperbola. The formula for finding the foci is derived algebraically and then applied to a specific hyperbola equation. Shows that the foci of a hyperbola relate closely to the foci of an ellipse....

A video lesson introducing conic sections. Includes a sketch of each of the four fundamental conic sections in two dimensions. Also explains why they are called conic sections by illustrating how each is the intersection of a cone and a...

A video lesson that provides instruction on finding the focus and directrix of a parabola. The majority of the video shows how the formulas for the focus and directrix are derived. Then a concrete example is given and the formulas are...

A video lesson showing the algebraic relationship between the equation of an arbitrary hyperbola and its arbitrary tangent line. [10:04]

The video tutorial discusses conic sections. Students learn about ellipses. The resource consists of examples with detailed explanations. [14:14]