Section 1.6

There are 2 limits you need to memorize and they are both found in Theorem 1.6.5. The first one is the one used predominantly in the homework. Remember that x stands for any number. Thus we also know that  .

For the problems (17, 18) for which x is approaching , first find the limit of the expression in the parentheses, then take the sine or cosine of that answer.

For problems 1-8, keep two things in mind.

1. The composition of continuous functions is continuous.
2. A function is discontinuous where its denominator is zero. If it doesn’t have a denominator (e.g. #’s 3-5), use a trig identity to rewrite it as a fraction.