>>11006493If you look at
>>11005200t runs from a to b (a<=t<=b)
and u runs from 0 to v(t) (0<=u<=v(t))
The u<=v(t) is the part to keep in mind.
Swapping the order of integration gives:
u runs from 0 to v_max
and t must be restricted to the values where u<=v(t).
Basically, instead of using vertical rectangles to do the riemann sum, you are using horizontal rectangles.
