# Primitive of Reciprocal/Corollary 2

## Corollary to Primitive of Reciprocal

- $\displaystyle \frac {\d} {\d x} \ln \size x = \frac 1 x$

for $x \ne 0$.

## Proof

Follows directly from Primitive of Reciprocal.

$\blacksquare$

## Sources

- 2005: Roland E. Larson, Robert P. Hostetler and Bruce H. Edwards:
*Calculus*(8th ed.): $\S 5.1$