# Thread: Another exact equation prob.

1. ## Another exact equation prob.

Determine whether the equation is exact. If it is exact, then solve the equation.

$\displaystyle ((y/x) +6x)dx+(lnx-2)dy=0$

My books answer key says that this equation is exact, but I don't see how. Your $\displaystyle M=(y/x)+6x$ and your $\displaystyle N=lnx-2$.

So taking the partial derivative $\displaystyle M_y=(1/x)+6x$and $\displaystyle N_x=1/x$.

I am pretty sure this is correct, so how is it possible that the equation is exact if the two partial derivatives are not equal?

2. Originally Posted by steph3824
Determine whether the equation is exact. If it is exact, then solve the equation.

$\displaystyle ((y/x) +6x)dx+(lnx-2)dy=0$

My books answer key says that this equation is exact, but I don't see how. Your $\displaystyle M=(y/x)+6x$ and your $\displaystyle N=lnx-2$.

So taking the partial derivative $\displaystyle M_y=(1/x)+6x$and $\displaystyle N_x=1/x$.

I am pretty sure this is correct, so how is it possible that the equation is exact if the two partial derivatives are not equal?
$\displaystyle M=(y/x)+6x$

$\displaystyle M_y=(1/x)$