Problem:
Use the bisection method to find a root of the function
f(x) = cos(x) - x.
Visualization:
Using JKGraph:
Since f(0) > 0 and f(1) < 0, we use the bisection method
on the closed interval [0,1].
- On the Formulas menu, choose Function Formula: Y=F(X).
- At the prompt F(X) = , type in
cos(x)-x
- Click on the button Edit Solve Domain.
- At the prompt, First Point X-Coordinate:, enter 0.
- At the prompt, Second Point X-Coordinate:, enter 1.
- At the prompt, Solution Method, click on Successive Bisections.
- At the prompt, Output Format, click on Graphical Output.
- At the prompt, Automatic/Manual, click on Automatic Animation.
- Click on the OK button.
- Click on the World Graph Domain button.
- At the prompt, Graph X Minimum Value:, enter 0.
- At the prompt, Graph X Maximum Value:, enter 1.
- At the prompt, Graph Y Minimum Value:, enter -1.
- At the prompt, Graph Y Maximum Value:, enter 1.
- Click on the OK button twice and you will see the graph of the
function.
- Finally, click on the Solve button and you will see the following
graph.

The approximation of the root appears at the bottom of the screen.