If $y = \log x$, what is $x\frac{d^2y}{dx^2} + \frac{dy}{dx}$?

Explanation

1. 01

   $\frac{dy}{dx} = \frac{1}{x}$ and $\frac{d^2y}{dx^2} = -\frac{1}{x^{2}}$.

2. 02

   $x \cdot \left(-\frac{1}{x^{2}}\right) + \frac{1}{x} = 0$.