Hi everyone. I'm trying to derive the formula for the characteristic age of a pulsar. What i'm starting with is the following differential equation. dP/dt=K*P2-n What i think is odd, is several places they say solving this differential equation gives the following solution. T=(P/((n-1)*dP/dt))*(1-(P0/P)n-1 Here is a picture of the equation too: But how do you get from equation 1. to this equation. Please help me out, if you could explain it step by step, i would really appreciate it. Because it doesn't make sense if you're trying to seperate both variables and integrate?