Exercise 2.2.3

Explain the meaning of each of the following.

(a) $\underset{x\to -3}{\lim <!--\; FUNCTION\; APPLICATION\; -->}f(x)=\infty$

(b) $\underset{x\to 4^{\text{+}}}{\lim <!--\; FUNCTION\; APPLICATION\; -->}f(x)=-\infty$