Integration Limits: Is Upper Limit Always Greater Than Lower?

[Miraj Kayastha]

is the upper limit always greater than the lower limit in integration?

what should be the limits if we need to calculate total work done in bringing a mass from infinity to distance r from earth.

 

[pwsnafu]

$\int_a^b f(x) \, dx = - \int_b^a f(x) \, dx$.

 

[PhysicoRaj]

what should be the limits if we need to calculate total work done in bringing a mass from infinity to distance r from earth.

_∞$\int$^r

 

[Boson]

There is decrease in potential energy of system. So, negative work is done. -{infinity to r}