Set .
Then .
So our integral becomes...
Posting working as I go along...
See attached images.
First one is the graph of
We want to know where this one crosses the x-axis.
Second one the graphs of of...
With the blue line representing .
We want to see where they cross.
This value is the p value I posted above. Maybe Opalg or Krizalid could give you a better answer but this is the best I can do for now.