Hi,

In the plot below I have .

The second graph of the plot shows that, for x = 1, the plot of has an infinite slope at (called the Poisson non-linear propagation solution).

I'm trying to show this analytically but not getting the right answer. I reproduce my steps below.

We want to show that for , has an infinite slope, i.e. .

we have , so

What I'm trying to show is , but that's clearly not possible from my result above.

Keen to hear where I'm going wrong. Thanks