##
Affine approximations

The graph on the right is a plot of the absolute value of the error in
approximating the square root function by an affine function passing through
(1,1) with the specified slope *m*. That is, the graph on the right is the graph of the absolute value of

.
The **Zoom in** button changes the scale of the
graph on the right by a factor of 0.5 in the horizontal direction and 0.25 in the vertical
direction; the **Zoom out** button changes the scale of the
graph on the right by a factor of 2 in the horizontal direction and 4 in the vertical
direction.