How to Find Intersection with the Axes in GeoGebra
You can either use CAS, or Algebra View and Graphics View together, to find where the graph of a function intersects the coordinate axes. The instructions for both methods are detailed below.
GeoGebra Instruction 1
Solution in CAS
- 1.
- Open
CASunder
Viewin
Menu. - 2.
- Type your function
f(x):=and pressEnter. - 3.
- To find the intersections with the -axis, type in
f(x)=0and clickSolve
to find the exact value, or Solve Numerically
to find a numeric approximation. The intersections with the -axis are the same as the zeros of the function . - 4.
- To find the intersection with the -axis, type
f(0)and pressSymbolic Evaluation
to find the exact solution, or Numeric Evaluation
to find a numeric approximation.
GeoGebra Instruction 2
Solution in Graphics View
- 1.
- Open
Algebra ViewandGraphics Viewunder Viewin Menu. - 2.
- Type your function into
Algebra Viewand pressEnter. - 3.
- In
Toolbar, selectIntersect
(it’s under the same toolbox as the Point
tool). - 4.
- Click the graph, and then one of the axes. Repeat for the other axis. The order doesn’t matter.
The intersection points between the graph and the axes are displayed in
Algebra View.
