https://www.khanacademy.org/math/geometry/xff63fac4:hs-geo-conic-sections/alg2-graphs-of-circles-intro/a/getting-ready-for-conic-sections 2026-04-27T15:00:44.807835298Z Getting ready for conic sections Practicing finding measurements in a circle, using the Pythagorean theorem, and completing the square will help us get ready for reasoning about conic sections (such as circles and parabolas). article https://www.khanacademy.org/math/geometry/xff63fac4:hs-geo-conic-sections/alg2-graphs-of-circles-intro/v/introduction-to-conic-sections 2021-05-26T15:51:55Z Intro to conic sections Sal introduces the four conic sections and shows how they are derived by intersecting planes with cones in certain ways. Sal Khan video https://cdn.kastatic.org/googleusercontent/RPWgYvDzMuiAzmQiOD9YRcWvZHF0dwBjlAHDhulF1J_WJKAg_F2Y44b_iZC_03pWPmyEhYAqttYl3kM1qUcvhoLh Intro to conic sections Sal introduces the four conic sections and shows how they are derived by intersecting planes with cones in certain ways. https://cdn.kastatic.org/ka-youtube-converted/0A7RR0oy2ho.mp4/0A7RR0oy2ho.mp4 658 Conic sections https://www.khanacademy.org/math/geometry/xff63fac4:hs-geo-conic-sections/hs-geo-circle-standard-equation/v/writing-standard-equation-of-circle 2022-10-07T00:00:24.225559754Z Writing standard equation of a circle Given a circle on the coordinate plane, Sal finds its standard equation, which is an equation in the form (x-a)²+(y-b)²=r². video https://cdn.kastatic.org/ka_thumbnails_cache/e02a9a45-7965-4d42-be70-a6f4d2bd2c79_1280_720_base.png Writing standard equation of a circle Given a circle on the coordinate plane, Sal finds its standard equation, which is an equation in the form (x-a)²+(y-b)²=r². https://cdn.kastatic.org/ka-youtube-converted/iX5UgArMyiI.mp4/iX5UgArMyiI.mp4 340 Conic sections https://www.khanacademy.org/math/geometry/xff63fac4:hs-geo-conic-sections/hs-geo-circle-standard-equation/e/write-the-equation-of-a-circle 2026-06-09T17:40:46.212160686Z Write standard equation of a circle Given the graph of a circle or its features, find its standard equation. Sid Patel exercise https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:ellipse-center-radii/v/conic-sections-intro-to-ellipses 2023-07-27T01:47:53.920337803Z Intro to ellipses Learn all about ellipses in this video. The standard form for an ellipse centered at the origin is x²/a² + y²/b² = 1. The semi-major axis is the longest radius and the semi-minor axis is the shortest radius. The video also explains how to shift an ellipse. Sal Khan video https://cdn.kastatic.org/googleusercontent/D5XS31KtD3HUL7SHsmzd_JIMx34-i0GpaT_aO8lkQ9ZJ-xQh8o_aqjYRbOoOi1pxn3PrusQB7Bl6CSkBWjBjmBHT Intro to ellipses Learn all about ellipses in this video. The standard form for an ellipse centered at the origin is x²/a² + y²/b² = 1. The semi-major axis is the longest radius and the semi-minor axis is the shortest radius. The video also explains how to shift an ellipse. https://cdn.kastatic.org/ka-youtube-converted/lvAYFUIEpFI.mp4/lvAYFUIEpFI.mp4 854 Conic sections https://www.khanacademy.org/math/ap-precalculus/xe322600f784e4778:functions-involving-parametric-vectors-and-matrices/xe322600f784e4778:conic-sections/v/writing-the-equation-of-an-ellipse-from-graph 2025-08-28T00:00:48.862639845Z Writing the equation of an ellipse from graph Write the equation of an ellipse when provided a graph by finding the radii of the major and minor axes. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/1d3860f3-731f-48fc-8932-9e4e5693f73f_1280_720_base.png Writing the equation of an ellipse from graph Write the equation of an ellipse when provided a graph by finding the radii of the major and minor axes. https://cdn.kastatic.org/ka-youtube-converted/pae1hExrc5o.mp4/pae1hExrc5o.mp4 205 Conic sections 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-center-radii/a/ellipse-features-review 2024-10-16T19:37:28.253855216Z Ellipse features review Review all the features of an ellipse: center, vertices, co-vertices, major radius, minor radius, and foci. article https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:ellipse-center-radii/a/ellipse-equation-review 2024-10-16T19:37:28.253855216Z Ellipse equation review Review your knowledge of ellipse equations and their features: center, radii, and foci. article https://www.khanacademy.org/math/geometry/xff63fac4:hs-geo-conic-sections/xff63fac4:hs-geo-parabola/v/equation-for-parabola-from-focus-and-directrix 2021-04-21T12:01:44Z Equation of a parabola from focus & directrix The equation of a parabola is derived from the focus and directrix, and then the general formula is used to solve an example. video https://cdn.kastatic.org/googleusercontent/E-dbou6Jw2dQISA_z84rO95zii-A6Xg1Z0p6X2F3Mn0ptl2V5adv0SPNIz9a-JLpoCh9lYmj6Mh1IKo_43AhuBrw Equation of a parabola from focus & directrix The equation of a parabola is derived from the focus and directrix, and then the general formula is used to solve an example. https://cdn.kastatic.org/ka-youtube-converted/okXVhDMuGFg.mp4/okXVhDMuGFg.mp4 588 Conic sections https://www.khanacademy.org/math/geometry/xff63fac4:hs-geo-conic-sections/xff63fac4:hs-geo-parabola/v/focus-and-directrix-introduction 2021-04-21T12:01:44Z Intro to focus & directrix A parabola is the set of all points equidistant from a point (called the "focus") and a line (called the "directrix"). See this video to learn more about this. video https://cdn.kastatic.org/googleusercontent/vHEIbri_Ra7d2MGcjent-C6nyMncsnZ_bZrmVsB1k3VSQZfThO4So8QnSbdlsjT_6xg2cjqoS3ZaQEpF0xy_OYid Intro to focus & directrix A parabola is the set of all points equidistant from a point (called the "focus") and a line (called the "directrix"). See this video to learn more about this. https://cdn.kastatic.org/ka-youtube-converted/pe8Dm_FUpdU.mp4/pe8Dm_FUpdU.mp4 247 Conic sections https://www.khanacademy.org/math/geometry/xff63fac4:hs-geo-conic-sections/xff63fac4:hs-geo-parabola/e/equation-of-parabola-from-focus-and-directrix 2026-06-09T17:40:46.212160686Z Equation of a parabola from focus & directrix Given the focus and the directrix of a parabola, derive its equation. Sid Patel exercise https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:hyperb-intro/v/conic-sections-intro-to-hyperbolas 2021-03-19T16:21:24Z Intro to hyperbolas Sal introduces the standard equation for hyperbolas, and how it can be used in order to determine the direction of the hyperbola and its vertices. Sal Khan video https://cdn.kastatic.org/googleusercontent/K7U1uh1j_MEI_Mc2X2xyfTTawjdJyVbxFn2XFN_np1nCX-ly_ohMlRgH-rScJ2tOKC-gLmyJHvByWl_Ri6Mt6Tyl Intro to hyperbolas Sal introduces the standard equation for hyperbolas, and how it can be used in order to determine the direction of the hyperbola and its vertices. https://cdn.kastatic.org/ka-youtube-converted/pzSyOTkAsY4.mp4/pzSyOTkAsY4.mp4 814 Conic sections https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:hyperb-intro/v/vertices-and-direction-of-a-hyperbola 2022-10-07T00:22:18.752150461Z Vertices & direction of a hyperbola Sal picks the graph of y²/9-x²/4=1 based on the hyperbola's center, direction, & vertices. video https://cdn.kastatic.org/ka_thumbnails_cache/fa4ee925-7989-43f1-a9dd-0592d0d9f175_1280_720_base.png Vertices & direction of a hyperbola Sal picks the graph of y²/9-x²/4=1 based on the hyperbola's center, direction, & vertices. https://cdn.kastatic.org/ka-youtube-converted/oO3nWnJppqg.mp4/oO3nWnJppqg.mp4 315 Conic sections https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:hyperb-foci/v/foci-of-a-hyperbola 2021-03-19T16:21:24Z Foci of a hyperbola from equation Sal discusses the foci of hyperbolas and shows how they relate to hyperbola equations. Sal Khan video https://cdn.kastatic.org/googleusercontent/fN5xNEwDo7pABBo-PQVKZcs8fLgu9rFMFTSrHmvDyAHXKycHCAM8e5YS5-tCZmXF6JtwrXfVQ8WaMIHLa9rtgoo Foci of a hyperbola from equation Sal discusses the foci of hyperbolas and shows how they relate to hyperbola equations. https://cdn.kastatic.org/ka-youtube-converted/S0Fd2Tg2v7M.mp4/S0Fd2Tg2v7M.mp4 924 Conic sections https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:non-origin-hyperb/v/conic-sections-hyperbolas-3 2021-03-19T16:21:24Z Equation of a hyperbola not centered at the origin Sal analyzes the hyperbola whose equation is (x-1)^2/16-(y+1)^2/4=1, and graphs it. Sal Khan video https://cdn.kastatic.org/googleusercontent/VFpEIZ1XOiIzH_CEkT2hwpLXC2jmCAKFh4IpbsPQACXWlv0mWZezY3T-HRV9cFiYwAsZBwwUraAPZQdPIJ9UUlAt Equation of a hyperbola not centered at the origin Sal analyzes the hyperbola whose equation is (x-1)^2/16-(y+1)^2/4=1, and graphs it. https://cdn.kastatic.org/ka-youtube-converted/lGQw-W1PxBE.mp4/lGQw-W1PxBE.mp4 629 Conic sections https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:conics/x9e81a4f98389efdf:hyperb-foci/e/equation_of_a_hyperbola 2026-05-05T18:10:50.367167117Z Equation of a hyperbola from features Given some features of a hyperbola, find its equation. Sid Patel exercise