# Math Help - easy derivative question

1. ## easy derivative question

I have a small question. I have to take the derivative of
y=(ln(x)+c)/x
i know i have to use the quotient rule but i dont know what to do with the derivative of c. Do i turn it into a one or drop ot all together. I am doing a diffyQ problem and that equation has to be a solution of
(x^2)y'+xy=1
i keep getting 1+x=1 so i think the "c" is messing me up.
Thanks for any help that anyone can provide

2. In taking derivatives, constants $c$ become $0$ while the independent variable (e.g., $x$) becomes $1$. This expresses the fact that while $x$ changes in direct proportion to a change in itself (by a factor of $1$), a constant $c$ simply does not change. In symbols,

\begin{aligned}
\frac{d}{dx}x&=1\\
\frac{d}{dx}c&=0.
\end{aligned}