Hi

Please have a look on the attachment. It has my question there. Please help me with it. Thank you very much.

Regards
PG

 

No, both terms (x^2y and g(y)) result from integrating the partial derivative ∂f/∂x.
Since y was held constant, g(y) is the "constant" of integration for ∫∂x.
After integrating ∂f/∂x to get f(x,y) you take ∂f/dy and set it equal to N to find g'(y). Then integrate to get g(y).