https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/v/using-the-quadratic-formula 2021-06-30T17:32:40Z The quadratic formula The quadratic formula helps us solve any quadratic equation. First, we bring the equation to the form ax²+bx+c=0, where a, b, and c are coefficients. Then, we plug these coefficients in the formula: (-b±√(b²-4ac))/(2a) . See examples of using the formula to solve a variety of equations. Sal Khan video https://cdn.kastatic.org/googleusercontent/x7GMr1ACeXuHJxVrjRWD7PnrOmWXP8RdAjYQyJIBuYA1UYmxrOwDqo4u3gWw57OamhGPgBEdToapBY9bOSG2-gbfwA The quadratic formula The quadratic formula helps us solve any quadratic equation. First, we bring the equation to the form ax²+bx+c=0, where a, b, and c are coefficients. Then, we plug these coefficients in the formula: (-b±√(b²-4ac))/(2a) . See examples of using the formula to solve a variety of equations. https://cdn.kastatic.org/ka-youtube-converted/i7idZfS8t8w.mp4/i7idZfS8t8w.mp4 992 Formula cuadrática https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/a/quadratic-formula-explained-article 2021-06-30T17:32:37Z Understanding the quadratic formula Gain more insight into the quadratic formula and how it is used in quadratic equations. article https://www.khanacademy.org/math/algebra-home/alg-quadratics/alg-solving-quadratics-using-the-quadratic-formula/v/quadratic-equations-in-standard-form 2020-12-28T16:56:57Z Worked example: quadratic formula Solving 6x²+3=2x-6 by rewriting in standard form and identifying the parameters a, b, and c, that can be used within the quadratic formula. Sal Khan video https://cdn.kastatic.org/googleusercontent/Xaj-daSLMDC1OjVEAWRMT8kckg2Q7YuVbWiqDREi4OR8Wi3vUOZEKA9Qu3DtVS-0CtMVyj_eEQYvL4_2o8mOdbdglg Worked example: quadratic formula Solving 6x²+3=2x-6 by rewriting in standard form and identifying the parameters a, b, and c, that can be used within the quadratic formula. https://cdn.kastatic.org/ka-youtube-converted/ty4Ohya4hdE.mp4/ty4Ohya4hdE.mp4 141 Formula cuadrática https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/v/quadratic-formula-2 2021-06-30T17:32:40Z Worked example: quadratic formula (example 2) Sal solves the equation -x^2+8x=1 by first bringing it to standard form and then using the quadratic formula. Sal Khan video https://cdn.kastatic.org/googleusercontent/V_OTYqvz0Vs_SXee7q3w9pxBm_LI-hlUpJHfTG6ntIEprr8GTNbKgoqDtqNWmVDKyd-2H_yHxAtfS-mm2ltubQRX Worked example: quadratic formula (example 2) Sal solves the equation -x^2+8x=1 by first bringing it to standard form and then using the quadratic formula. https://cdn.kastatic.org/ka-youtube-converted/CLrImGKeuEI.mp4/CLrImGKeuEI.mp4 400 Formula cuadrática https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/v/applying-the-quadratic-formula 2021-06-30T17:32:39Z Worked example: quadratic formula (negative coefficients) Sal solves -3x^2+10x-3=0 by plugging a=-3, b=10, c=-3 in the quadratic formula. Then he multiplies everything by -1 and solves again. The results are the same! Sal Khan video https://cdn.kastatic.org/googleusercontent/VZTEh4UutBXDxjGxuABZwxG9LaMkHXpBkzp-tS4O29i6ZoaXdlORU-fQYqBE1UXKXT06k7vmCsr7ipfTlEoh7Ko Worked example: quadratic formula (negative coefficients) Sal solves -3x^2+10x-3=0 by plugging a=-3, b=10, c=-3 in the quadratic formula. Then he multiplies everything by -1 and solves again. The results are the same! https://cdn.kastatic.org/ka-youtube-converted/_E3gx_yQhHQ.mp4/_E3gx_yQhHQ.mp4 291 Formula cuadrática https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/a/quadratic-formula-review 2021-06-30T17:32:37Z Quadratic formula review The quadratic formula allows us to solve any quadratic equation that's in the form ax^2 + bx + c = 0. This article reviews how to apply the formula. article https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/e/quadratic_equation 2025-12-28T12:18:45.238308434Z Quadratic formula Solve quadratic equations using the quadratic formula. For example, solve -9x+10x²+8=14. exercise https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/v/quadratic-formula-3 2021-06-30T17:32:40Z Using the quadratic formula: number of solutions Sal determines how many solutions the equation x²+14x+49=0 has by considering its quadratic formula, and more specifically, its discriminant. Sal Khan video https://cdn.kastatic.org/googleusercontent/tME4PRNM9reIhRtam5gf08p-f3rTVvAUySKkYVhiXETYW2OVGb067h40e5z7ZvPDtCie_-_v3GpBKKAH1CckUb-I Using the quadratic formula: number of solutions Sal determines how many solutions the equation x²+14x+49=0 has by considering its quadratic formula, and more specifically, its discriminant. https://cdn.kastatic.org/ka-youtube-converted/XUvKjC21fYU.mp4/XUvKjC21fYU.mp4 299 Formula cuadrática https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/a/discriminant-review 2023-06-13T22:35:48.054857993Z Discriminant review The discriminant is the part of the quadratic formula underneath the square root symbol: b²-4ac. The discriminant tells us whether there are two solutions, one solution, or no solutions. article https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:quadratic-functions-equations/x2f8bb11595b61c86:quadratic-formula-a1/e/determine-the-number-of-solutions-of-a-quadratic-equation 2025-12-28T12:18:45.238308434Z Number of solutions of quadratic equations Analyze quadratic equations in order to determine how many different real number solutions they have. Tomer Gal exercise