Final answer:
A vertical asymptote of y=f(x) means that as x approaches a, the values of y approach positive or negative infinity.
Step-by-step explanation:
To say that x=a is a vertical asymptote of y=f(x) means that as x approaches a, the values of y approach positive or negative infinity. In other words, the graph of f(x) approaches but never touches the line x=a. The vertical asymptote can be found by determining the values of x for which f(x) is undefined or approaches infinity.