A vertical asymptote (VA) is an invisible line that a graph approaches but never touches. It is represented by a vertical dotted line and can appear to coincide with a function's graph. VAs are important when graphing functions and can occur when x can't equal a certain value. For example, if you graph
𝑦=1/𝑥, you'll see that x can't equal zero, so there is a VA at 𝑥=0.
