### Home > CALC > Chapter 4 > Lesson 4.4.1 > Problem 4-126

4-126.

Sketch below and determine if it is differentiable at

*.*

Differentiability implies continuity. If you are checking for differentiability, you also need to check for continuity.

To check for continuity:

Verify that:

and verify that:

is continuous at

*.*

To check for differentiability:

Verify that:

............................

Since both and

*are continuous at*

*,*

*is differentiable at*

*.*