https://www.khanacademy.org/math/ap-calculus-ab/ab-integration-new/ab-6-3/v/sigma-notation-sum 2026-06-25T15:40:55.094699315Z Understanding summation notation Sigma notation is the standard notation for writing long sums. Learn how it is used in this video. Sal Khan video https://cdn.kastatic.org/googleusercontent/AkUo89aMk-ZXH2KwZTUALeYknZORIY--gS_3ht52xZLOfQSEU8xfeGgm3Ohz0IeLeNCwAh0j_7M_tfBySGHDGA Understanding summation notation Sigma notation is the standard notation for writing long sums. Learn how it is used in this video. https://cdn.kastatic.org/ka-youtube-converted/5jwXThH6fg4.mp4/5jwXThH6fg4.mp4 267 Geometric series (with summation notation) https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:series/x9e81a4f98389efdf:geo-series-notation/e/evaluating-basic-sigma-notation 2025-03-01T15:52:37.13987578Z Summation notation intro Evaluate expressions that use sigma notation to make sure you understand what sigma notation means. Ben Stenhaug exercise https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:series/x9e81a4f98389efdf:geo-series-notation/v/geometric-series-introduction 2021-06-30T17:32:39Z Geometric series with sigma notation A geometric series is the sum of the terms of a geometric sequence. Learn about geometric series and how they can be written in general terms and using sigma notation. Sal Khan video https://cdn.kastatic.org/googleusercontent/edm1JFw4GPOT7T8ljd68cDJebFceDMpVC_LLDcIkw_R9COsHIsH7RPpsbz8-3B-lZqOM2y4yMGEmL6t9K4W-LbCdUw Geometric series with sigma notation A geometric series is the sum of the terms of a geometric sequence. Learn about geometric series and how they can be written in general terms and using sigma notation. https://cdn.kastatic.org/ka-youtube-converted/CecgFWTg9pQ.mp4/CecgFWTg9pQ.mp4 268 Geometric series (with summation notation) https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:series/x9e81a4f98389efdf:geo-series-notation/v/example-finding-sum-of-finite-geometric-series 2022-10-07T00:22:18.752150461Z Worked example: finite geometric series (sigma notation) Sal evaluates the geometric series Σ2(3ᵏ) for k=0 to 99 using the finite geometric series formula a(1-rⁿ)/(1-r). video https://cdn.kastatic.org/ka_thumbnails_cache/141f5f44-3e3e-41de-87b2-89e059c39be5_1280_720_base.png Worked example: finite geometric series (sigma notation) Sal evaluates the geometric series Σ2(3ᵏ) for k=0 to 99 using the finite geometric series formula a(1-rⁿ)/(1-r). https://cdn.kastatic.org/ka-youtube-converted/AXP5PGSaaYk.mp4/AXP5PGSaaYk.mp4 168 Geometric series (with summation notation) https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:series/x9e81a4f98389efdf:geo-series-notation/e/geometric-series--1 2025-03-01T15:52:37.13987578Z Finite geometric series Evaluate finite geometric series given in sigma notation, recursively, or explicitly. Tomer Gal exercise https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:series/x9e81a4f98389efdf:geo-series-notation/v/geometric-series-word-problem 2021-06-30T17:32:39Z Finite geometric series word problem: social media Watch Sal solve an example of using a geometric series to answer a fun word problem. Sal Khan video https://cdn.kastatic.org/googleusercontent/v392FVECsH38yNQR1hy859u7azBi8uS6CKMVJ46EXTVbf4IxS6Uqk6tB2q18Mi4GAjufHWcG7phlDJvsU-JSeohC8A Finite geometric series word problem: social media Watch Sal solve an example of using a geometric series to answer a fun word problem. https://cdn.kastatic.org/ka-youtube-converted/aIjzkiijGnA.mp4/aIjzkiijGnA.mp4 483 Geometric series (with summation notation) https://www.khanacademy.org/math/precalculus/x9e81a4f98389efdf:series/x9e81a4f98389efdf:geo-series-notation/v/geometric-series-sum-to-figure-out-mortgage-payments 2021-12-17T18:23:14.765077602Z Finite geometric series word problem: mortgage Figuring out the formula for fixed mortgage payments using the sum of a geometric series Sal Khan video https://cdn.kastatic.org/googleusercontent/CgfMgZ3rm608Ddywe6L6DH4PtsD4KWw-e4DKjzRNPDk2NihbrHrPuXHLx1VlgIkdyNKD2xo2XQxFr4QvxtOzVNo Finite geometric series word problem: mortgage Figuring out the formula for fixed mortgage payments using the sum of a geometric series https://cdn.kastatic.org/ka-youtube-converted/i05-okb1EJg.mp4/i05-okb1EJg.mp4 1056 Geometric series (with summation notation)