Cogito
Calculus · Chapter 3 · Lesson 3
Differentiability
Where a function has no slope at all.
12 problems · about 21 minutes · FUN-2.A
Figure — use these to answer the problems
Warm Up
Straightforward practice. Get the method working first.
5 problemsy = |x − 2|. At which x is the derivative undefined?
AnswerWhich statement is true?
- Differentiable implies continuous, but not the reverse.
- Continuous implies differentiable.
For y = |x|, the slope just right of zero?
AnswerA function is continuous at x = 2. Must it be differentiable there? 1 or 0.
Answery = |x − 4|. At which x is it not differentiable?
Answer
Build It Up
The same ideas with more to keep track of.
3 problemsA graph jumps at x = 1. Is it differentiable there? 1 or 0.
Answery = x². Is it differentiable at x = 0? 1 or 0.
AnswerAt a vertical tangent, is the derivative defined? 1 or 0.
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsWhich situations block differentiability?
- A corner
- A vertical tangent
- A jump
- A horizontal tangent
- Tick every box that applies.
y = |x + 7|. At which x is it not differentiable?
AnswerThe Corner
For y = |x|, what is the slope just to the left of zero?
AnswerThe Implication
A function is differentiable at x = 3. Must it be continuous there? 1 for yes, 0 for no.
Answer