Final answer:
As b approaches 0, the expression a/b approaches infinity or negative infinity depending on the signs of a and b. This occurs because dividing a nonzero number by a number that gets closer and closer to 0 results in a value that increases without limit.
Step-by-step explanation:
When considering the expression a/b, where a is a nonzero constant and b approaches 0, we deal with a concept referred to in calculus as a limit.
As b approaches 0, the value of a/b becomes increasingly large in magnitude. If b approaches 0 from the positive side, a/b approaches positive infinity if a is positive, and negative infinity if a is negative. Conversely, if b approaches 0 from the negative side, a/b approaches negative infinity if a is positive, and positive infinity if a is negative. This behavior can be described by saying that a/b has an asymptote as b approaches 0. The reason for this is that you are dividing a nonzero number by an increasingly small number, which results in a value that grows without bound.