Hi Sean

Yeah you can do a substitution for the U on RHS:

y = integral ( o to tau) U(t)dt

then dy/dt = THE WHOLE RHS with y instead of the U integral

The paper I got this equation from said it has a analytical solution if we find it using Mathematica or Maple.

I solved the equation numerically using the above substitution but I need to add something to it and it becomes harder to do it numerically after my modification to the equation

Mayur