# How to Find Stationary Points in GeoGebra

You can use `GeoGebra` to find the stationary points of a function. One method involves using `CAS`. Another way is to use `Algebra View` and `Graphics View`.

Recall that `Solve`  yields exact answers (fractions and roots), while `Solve Numerically`  yields approximated answers given as decimal numbers.

`GeoGebra` Instruction 1

### StationaryPointsin`CAS`

1.
Open `CAS` under  `View` in  `Menu`.
2.
Input your function using `f(x):=`. Then press `Enter`.
3.
To differentiate your function, click the expression in the previous row so that it is copied to the current one. Select the `Derivative`  tool.
4.
Click the expression of the derivative. Type `=0` after the expression and press `Solve`  or `Solve Numerically` .
5.
To find the coordinates of the maxima and minima, you need to calculate the corresponding $y$-values. To do this, type `f(x-value)` and then press `Enter`. Do this for all the $x$-values you have found.
6.
To determine visually if a point is a maximum, minimum or inflection point, you can look at the graph displayed in `Graphics View`.

If you only want to find the extrema (maxima or minima) of a function, you can just use `Graphics View`.

`GeoGebra` Instruction 2

### Extremain`Graphics View`

1.
Open `Algebra View` and `Graphics View` under  `View` in  `Menu`.
2.
Enter your function into `Algebra View` and then press `Enter`.
3.
To find the extrema of the function, type

Extremum(<Function>, <Start x-Value>, <End x-Value>)

in `Algebra View`.

Enter the function name ($f\left(x\right)$, $g\left(x\right)$, and so on) for `<Function>`. For `<Start>` and `<End>`, choose a sufficient interval based on the plotted graph. For `<Start>`, choose an $x$-value to the left of all the extrema of the graph, and for `<End>`, choose an $x$-value to the right of all the extrema of the graph.