DateDefine IntegralsUpper limit of integrationIntegrationsymbolf (x) dxIntegrandVariable of integrationLower limit(dummy variable)of integrationIt is called a dummyvariable because the answerdoes not depend on the variblechosen.nlim E ((G) AXLeibnitz introduced a simplernisk=1notation for the definite integranlim(CC) DX(x) dxn-> a kcsDefinitionNote that very smallArea Under a curvechange in X become dxIf y= F(x) is non negative and integrableover a closed interval [a,b], then area underthe curve y f(x) from a to b is theintegral of f from a to b.A=f (x) dxa