I need to show that this diff eq$\displaystyle (x+3x^3siny)dx+x^4cosy\ dy=0$ is not exact and multiply it by $\displaystyle \frac{1}{x}$ to make it exact..
thanks
for 1st part i partial diff it wrt y to get $\displaystyle 3x^3cosy$ and 2nd part wrt x to get $\displaystyle 4x^3cosy$...
thereafter, do I need to multiply it by x throughout to make it exact?and the general solution is just solving it like a separable diff eq right?