and the term in front of dy must be , WHERE the bottom line is to find that .
Ignore the silly N and M in must books, it's foolish.
Next from Clarabell's theorem
and in our case that's correct, we get in both cases.
So, it's exact. Hence integrate the wrt x
and wrt y to get this and when you integrate, don't just add +C
in the first case it's and the second it's .