https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:functions/x2f8bb11595b61c86:evaluating-functions/v/what-is-a-function 2021-06-30T18:10:09Z What is a function? Functions assign a single output for each of their inputs. In this video, we see examples of various kinds of functions. Sal Khan video https://cdn.kastatic.org/googleusercontent/whRX1xQJEDdGcWfqUl8w5525C24vlDY-jZPlw-V9OTDxzG7Adv25nPLwbaP1FKUH4HK6R7YTRYoSCB9n4fLieb7A What is a function? Functions assign a single output for each of their inputs. In this video, we see examples of various kinds of functions. https://cdn.kastatic.org/ka-youtube-converted/kvGsIo1TmsM.mp4/kvGsIo1TmsM.mp4 477 Functions https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:functions/x2f8bb11595b61c86:evaluating-functions/v/understanding-function-notation-example-1 2021-06-30T18:10:08Z Worked example: Evaluating functions from equation Learn how to evaluate f(x)=49-x² at x=5. Sal Khan video https://cdn.kastatic.org/googleusercontent/03JkypsEnHQbMacEEnDhM2q7NzHC0H8z9r5kzGCVuoZU6lPVF8p6FjvFPLQR4CeQfKoJkRVn0ROCTWHfZTMhBDST Worked example: Evaluating functions from equation Learn how to evaluate f(x)=49-x² at x=5. https://cdn.kastatic.org/ka-youtube-converted/Id6UovYjd-M.mp4/Id6UovYjd-M.mp4 59 Functions https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-linear-equations-functions/8th-functions-and-function-notation/e/evaluate-functions 2026-04-07T22:59:30.107127435Z Evaluate functions Evaluate functions for specific inputs given the formula of the function. Lindsay exercise https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:functions/x2f8bb11595b61c86:evaluating-functions/v/understanding-function-notation-example-2 2021-06-30T18:10:10Z Worked example: Evaluating functions from graph Evaluating a function at x=-1 using the graph of that function. Sal Khan video https://cdn.kastatic.org/googleusercontent/rut742_LAfXpdb93Uk5lXue9m1yQuXStNvQkA3Ts6i_NZSMPTq2v6e4uPyFb9qkdLHy_pI1Jfzhg_aILSJVs9aYq Worked example: Evaluating functions from graph Evaluating a function at x=-1 using the graph of that function. https://cdn.kastatic.org/ka-youtube-converted/kzYtx_AqzjM.mp4/kzYtx_AqzjM.mp4 44 Functions https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-linear-equations-functions/8th-functions-and-function-notation/e/evaluate-functions-from-graph 2026-03-25T20:00:51.494577527Z Evaluate functions from their graph Evaluate functions for specific inputs given the graph of the function. Lindsay exercise https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:functions/x2f8bb11595b61c86:functions-and-equations/v/difference-between-equations-and-functions 2021-06-30T18:10:09Z Equations vs. functions Equations and functions are not the same thing, but they can be related in several ways. Watch Jesse Roe and Sal talk about the difference between equations and functions Sal Khan video https://cdn.kastatic.org/googleusercontent/_SP6Z0ZojobmwUjesasgEIFIaGMT7_zcEJh29GwRKFy0jHOihhhUI_kb-rMiZGErLXeiltjt9ltH3XO51uJofPrgAg Equations vs. functions Equations and functions are not the same thing, but they can be related in several ways. Watch Jesse Roe and Sal talk about the difference between equations and functions https://cdn.kastatic.org/ka-youtube-converted/l3iXON1xEC4.mp4/l3iXON1xEC4.mp4 258 Functions https://www.khanacademy.org/math/algebra/x2f8bb11595b61c86:functions/x2f8bb11595b61c86:functions-and-equations/v/create-function-from-equation 2021-06-30T18:10:12Z Obtaining a function from an equation Equations and functions are not the same thing, but they can be related in several ways. In this video, we obtain a function from an equation. The function represents the same relationship between the quantities in the equation. video https://cdn.kastatic.org/googleusercontent/F5S3uNH6KPziMrVcipDuh6xArm7ofSX7yF1KNBC9Xwayqm9zyuVr9nr9egRMriZUjNb5JjG-xFkxmXEHg3l100P0 Obtaining a function from an equation Equations and functions are not the same thing, but they can be related in several ways. In this video, we obtain a function from an equation. The function represents the same relationship between the quantities in the equation. https://cdn.kastatic.org/ka-youtube-converted/OOim0QPsJ9o.mp4/OOim0QPsJ9o.mp4 184 Functions https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-linear-equations-functions/8th-functions-and-function-notation/e/function-rules-from-equations 2021-06-30T18:10:12Z Function rules from equations Create functions that match one variable to the other in a two-variable equation. Lindsay exercise