CAS (Computer Algebra System) is the calculator in GeoGebra, and has its own view. Open it by clicking CAS under
View in
Menu.
In this entry, we’ll take a look at the basics of CAS. If you want to learn how to use CAS for a specific task in a given subject, like solving systems of equations or differentiation, check out the respective GeoGebra entries. The entries are categorized by subject.
By typing your calculation into an empty row in CAS and pressing Enter, CAS will do the calculation for you.
GeoGebra Instruction 1
Open CAS under
View in
Menu.
To add , type
36 + 87
and press Enter.
To subtract , type
143 - 46
and press Enter.
To multiply , type
13 * 15
and press Enter.
To divide , type
132 / 12
and press Enter.
GeoGebra Instruction 2
CAS under View in Menu. To calculate , type x^p and press Enter.
Roots:
To calculate , type x^1/n and press Enter.
If want to compute a square root, you can use the command sqrt(<x>) instead. sqrt is short for “square root”.
Note! GeoGebra only prints the positive root, even if there’s a negative root too.
Algebraic expressions work the same way, but make sure that you use the multiplication symbol (*) between the individual symbols. If you for example type ab, GeoGebra will interpret it as an object with the name “ab”, and not .
GeoGebra Instruction 3
Open CAS under
View in
Menu.
To compute , type
2a + 3a
and press Enter.
To compute , type
a * b * b^2
and press Enter. You get . If you type
ab * b^2
you get , because GeoGebra interprets ab as an object, and not the product .
If you want to type a fraction in CAS, you need to add a fraction bar (also known as “vinculum”). Here’s how you do it:
GeoGebra Instruction 4
CAS under View i Menu. /. A fraction bar should appear, which consists of two empty fields for the numerator and the denominator, respectively. Type the numerator of your fraction first, and then click on the second field and type your denominator. Press Enter when you’re done. Note! CAS simplifies fractions automatically.
CAS can also be used for rounding numbers.
GeoGebra Instruction 5
CAS under View i Menu. round(<x>)
where you replace <x> with your number.
round(<x>, <y>)
where you replace <x> with your number, and <y> with the number of decimal places.
You can also calculate powers and roots in CAS.
By clicking Expand in the
CAS Toolbar, you can expand parentheses.
GeoGebra Instruction 6
CAS under View in Menu. CAS and click Expand Toolbar.
CAS can be used to factorize an expression. If it doesn’t change after clicking Factor , it can’t be factorized.
Note! GeoGebra uses the term factor instead of factorize.
GeoGebra Instruction 7
CAS under View in Menu. CAS and click Factor Toolbar.