# What is the domain of f(x)=tanx?

The domain of $\tan x$ is all real numbers except $\frac{\pi}{2} + \pi n$ where $n$ is an integer. The graph of $\tan x$ is shown below:
The graph of $\tan x$ has an asymptote at $\frac{\pi}{2}$, and the period of the function is $\pi$, meaning the asymptote repeats and the function is undefined every $\pi$ units in the x-direction.