Skip to main content

Activity 4.3 Nondifferentiability

A function is said to be nondifferentiable at any value where its first derivative is undefined. There are three graphical behaviors that lead to nondifferentiability.
  • \(f\) is nondifferentiable at \(a\) if \(f\) is discontinuous at \(a\text{.}\)
  • \(f\) is nondifferentiable at \(a\) if the slopes of \(f\) from the left and from the right at \(a\) are different.
  • \(f\) is nondifferentiable at \(a\) if \(f\) has a vertical tangent line at \(a\text{.}\)

Exercises Exercises

Exercise Group.

Consider the function \(k\) shown in the first figure. Please note that \(k\) has a vertical tangent line at \(-4\text{.}\)

1.

There are four values where \(k\) is nondifferentiable; what are these values?

2.

Draw \(\fd{k}\) onto the second figure.

Exercise Group.

Consider the function \(g\) shown in the first figure.

3.

\(\fd{g}\) has been drawn onto the second figure over the interval \(\ointerval{-5}{-2.5}\text{.}\) Use the piecewise symmetry and periodic behavior of \(g\) to help you draw the remainder of \(\fd{g}\) over \(\ointerval{-7}{7}\text{.}\)

4.

What six-syllable word applies to \(g\) at \(-5\text{,}\) \(0\text{,}\) and \(5\text{?}\)

5.

What five-syllable and six-syllable words apply to \(\fd{g}\) at \(-5\text{,}\) \(0\text{,}\) and \(5\text{?}\)