Recent content by Pinali

Ah yeah, I just managed it. I did indeed get a log which was apparently correct (it yielded the correct answer anyway when I applied the initial conditions), so thank you for the help. The arctan thing it seems was for use later on, which I also managed okay when I realized it. Thanks again!

Ah sorry typing error. It meant to be y"=-b - c(y')² the original equation, not just y' by itself. And the signs wrong too, argh, I am silly. v dv/dy = - b - c v² dv/dy = - (b + c v²)/v So then - § v / (b + c v²) dv = § 1 dy - 1/b § v / (1 + d v²) dv = y + p d is another constant that I choose...

In order to explain what I have to do here, I'm trying to solve the autonomous nonlinear ODE y"=b+cy' where b and c are constants. My lectures showed how to do this using the substitution v=y' and so y"=v*dv/dy. I then separated variables to get the above integral. Maybe it's just the fact that...

Hi. I've been struggling with this for hours and not getting anywhere even after a hint from a teacher. I have to integrate (indefinite integral) v / (1+cv²) where c is a constant. The hint the teacher gave was that the integral of 1 / (1+v²) is tan^-1(v), but I can't see how to use this...