## Calculus with Applications (10th Edition)

Using symols, for $a>0, a\neq 1$, and $x>0$, $y=\log_{a}x$ means $a^{y}=x$. In words, y, the logarithm (base a) of a chosen number (x) is the exponent to which the base a must be raised ($a^y$) to obtain the chosen number (x)