Cogito
AP Calculus AB · Chapter 1 · Lesson 3
Computing Limits and Indeterminate Forms
What to do when substitution fails.
12 problems · about 22 minutes · LIM-1.D, LIM-1.E
Figure — use these to answer the problems
- Point(1, 2)
Warm Up
Straightforward practice. Get the method working first.
5 problemsLimit of (x² − 1) ÷ (x − 1) as x approaches 1?
AnswerWhat does the Squeeze Theorem require?
- The function is trapped between two others sharing a limit.
- The function is continuous.
Limit of (x² − 4) ÷ (x − 2) as x approaches 2?
AnswerLimit of (x² − 25) ÷ (x − 5) as x approaches 5?
AnswerLimit of (x³ − 8) ÷ (x − 2) as x approaches 2?
Answer
Build It Up
The same ideas with more to keep track of.
3 problemsLimit of (1 − cos x) ÷ x as x approaches 0?
AnswerLimit of 5x + 2 as x approaches 3?
Answerg is trapped between −x² and x² near 0. What is its limit there?
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsSort each form by what it tells you.
Write each item under the heading it belongs to: Zero over zero · Infinity minus infinity · Five over zero · Negative three over zero
More work needed
Limit does not exist
Limit of (x² − 16) ÷ (x + 4) as x approaches −4?
AnswerThe Cancel
Limit of (x² − 9) ÷ (x − 3) as x approaches 3?
AnswerThe Special Limit
Limit of sin x ÷ x as x approaches 0?
Answer