3.3.19 Not exact first order ode where integrating factor is found by inspection

ode internal name "exactByInspection"

This has the form \(M\left ( x,y\right ) +N\left ( x,y\right ) y^{\prime }=0\) where \(\frac {\partial M}{\partial y}\neq \frac {\partial N}{\partial x}\) (i.e. the ode is not exact) and none of the above three known methods for finding integrating factor were successful. This solver uses trial and error using a number of built-in common integrating factor to see if any one of them makes the ode exact.