Question

What is the logarithm of a negative number?

Answer 1

Find the logarithm of a negative number.

The logarithmic function $y={\log }_b\left(x\right)$ is the inverse function of the exponential function such that $x=b^y$
Because the base $b$ is positive $(b>0)$, any real $y$ must have a positive $\left(b^y>0\right)$ base $b$ raised to the power of $y$.

Since, $x$ must be a positive value $(x>0)$.

A negative number's real base $b$ logarithm is undefined.
Thus, ${\log }_b\left(x\right)$ is undefined for$x\le 0$