# Difference between revisions of "Getting started with KAlgebra/da"

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Kalgebra er et regneprogram med symbolske og analytiske faciliteter, som både lader dig tegne grafer og 3D-plots og arbejde med matematiske udtryk.

## Fanebladet Konsol

Lige når du starter KAlgebra, så ser du et tomt vindue; det er hovedsaligt her du arbejder med beregninger.

Lad os komme i gang med et lille eksempel på, hvordan KAlgebra virker. Skriv

`2+2`

og tast så Enter. Kalgebra viser dig så resultatet. Det var nemt nok.

Men KAlgebra kan meget mere end det. Den startede som et enkelt regneprogram, mer er nu næsten et CAS-program.

Du kan definere variable således:

`k:=3`

og bruge dem normalt:

`k*4`

Det vil give resultatet

`12`

You can also define functions:

`f:=x->x^2`

And then use them:

`f(3)`

Which should return

`9.`

You can define a function with as many variables as you want:

`g:=(x,y)->x*y`

The possibilities of defining functions are endless if you combine this with the piecewise function. Let's define the factor function:

`fact:=n->piecewise { n=0 ? 1, n=1 ? 1, ? n*fact(n-1) }`

Yes! KAlgebra supports recursive functions. Give some values to n, to test it.

```fact(5)
fact(3)```

KAlgebra has recently started support for symbolic operations, to check it out, just type:

`x+x+x+x`

or

`x*x`

It doesn't work on some complex structures, though. Only basic support so far.

Moreover, KAlgebra has support for differentiation. An example of the syntax:

`diff(x^2:x)`

If you have used KAlgebra, you will have noticed the syntax completion support, which is very helpful.

Another resource that can be useful to learn more about KAlgebra comes with KAlgebra: The Dictionary tab

It contains examples of every function supported by KAlgebra. Maybe this is the best way to learn how to do things with KAlgebra.

This page was last edited on 10 October 2010, at 12:14. Content is available under Creative Commons License SA 4.0 unless otherwise noted.