*Problem:*

Graphically explore the linear approximation of the function
**y = f(x) = x**^{3} - 5x + 6
using the tangent line at **x = a** for various values of **a**.

*Visualization:*

Use the following Mathview Notebook which begins with the tangent line at
**x = a = 1** to zoom in at the point **(1, 2)** to see how well the
graph of the tangent line approximates the graph of **f**.
You can change the value of **a** and the function **f**.
View an animation to see how this can be done.