# How do you evaluate log_7 (-49)?

Aug 30, 2016

${\log}_{7} \left(- 49\right) \text{is undefined}$ in $\mathbb{R}$.

Aug 30, 2016

undefined

#### Explanation:

$y = {\log}_{7} \left(- 49\right)$. Then $y$ is the number such that ${7}^{y} = - 49$.

There is no real number $y$ that makes ${7}^{y} = - 49$ true, so it is undefined.

$\log x$ is undefined for $x \le 0$.