I've seen this formula stated and used, ( in a stanford university video lecture)(adsbygoogle = window.adsbygoogle || []).push({});

[tex] \int \frac{dA}{dt}B\ dt = - \int \frac{dB}{dt}A\ dt [/tex]

with the condition that you don't vary the end points.

but i don't understand how you can just remove the AB term from the right hand side, and i've not been able to find this written anywhere? i know the normal parts rule.

can anyone explain?

thanks

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# Integration by parts, can you do this?

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