https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:ellipse-foci/v/foci-of-an-ellipse 2021-03-19T16:21:24Z Foci of an ellipse from equation Sal explains how the radii and the foci of an ellipse relate to each other, and how we can use this relationship in order to find the foci from the equation of an ellipse. Sal Khan video https://cdn.kastatic.org/googleusercontent/Yz3g-FK-xyNlN0n9dnHPMLLICOGJjZ5vDhj2O6XmMgEDGMPOCwhfkz3GQlfRXITSUoq5mMNqlfllza9EQyRdjwGANA Foci of an ellipse from equation Sal explains how the radii and the foci of an ellipse relate to each other, and how we can use this relationship in order to find the foci from the equation of an ellipse. https://cdn.kastatic.org/ka-youtube-converted/QR2vxfwiHAU.mp4/QR2vxfwiHAU.mp4 829 Foci of an ellipse https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:ellipse-foci/e/find-foci-of-ellipse-from-radii 2026-04-08T00:54:09.631945657Z Foci of an ellipse from radii Given the major and minor radii of an ellipse, find its foci. Sid Patel exercise https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:ellipse-foci/e/foci-of-ellipse-from-equation 2025-03-01T15:52:37.13987578Z Foci of an ellipse from equation Given the equation of an ellipse, find its foci. Sid Patel exercise https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:ellipse-foci/e/equation-of-ellipse-from-foci 2025-08-13T18:55:53.294958456Z Equation of an ellipse from features Given the foci of an ellipse (and some other feature), find its equation. Sid Patel exercise https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:ellipse-foci/a/ellipse-foci-review 2024-10-16T19:37:28.253855216Z Ellipse foci review Review your knowledge of the foci of an ellipse. article