ABSTRACT

When using integration by parts, an integral such as ∫ x 2 e x  dx https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/eq4111.tif"/> requires integration by parts twice. Similarly, ∫ x 3 e x  dx https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/eq4112.tif"/> requires integration by parts three times. Thus, integrals such as ∫ x 5 e x  dx https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/eq4113.tif"/> , ∫ x 6 cos x  dx https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/eq4114.tif"/> and ∫ x 8 sin 2x dx https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429294402/968186b9-ffa4-4f2b-aa54-7fc58a604561/content/eq4115.tif"/> or example, would take a long time to determine using integration by parts. Reduction formulae provide a quicker method for determining such integrals.