Important Points About Function Entry


Because of the restrictions of a computer interface, there are some special points you will need to understand to enter all functions.


Special Symbols

Because mathematicians use many symbols not normally found on a computer keyboard, the graph tool uses a small number of special symbols, codes and abbreviations in order to allow you to enter functions.


Normal Symbol

the graph tool





Exponentiation (Powers)

none (eg 2x)

^ (eg 2^x)

Only needed when the graph tool fails to automatically recognise the power.



/ (followed by a space)

The / character is more often used (without the space) to enter fractions.




Can be used in both functions and axes.




Used in polar functions

Greater than or equal to


Less than or equal to


Plus Minus



the graph tool will automatically graph both arms of the function.


Most of these symbols are in common use in computer based mathematics.



Many functions, especially fractions, contain assumed brackets.  The graph tool will sometimes require you to enter these brackets even though you cannot see them.  For example,  if you enter y = 3/x+3 does this mean



To graph the second function you need to add logical brackets to your function and type  y = 3/(x+3).  These brackets will not be displayed but will influence how your function is interpreted.


As a general rule, if the function is not shown formatted correctly by the graph tool, add some brackets to make your meaning clear.


A very important use of brackets is to logically identify the numerator and denominator in complicated fractions. For example: (x+2)/(x-3) needs the brackets to be interpreted as clip0017  rather than clip0018 .


Brackets are also used to logically identify powers and ensure that the graph tool interprets your function correctly.


All three bracket types {, [ and ( may be used interchangeably in the graph tool and the graph tool makes no distinction between them.  the graph tool does not even check to see if brackets are paired.  You are responsible for this.  If there is a fraction inside a bracket, the bracket is automatically resized.



clip0019                is entered as 3[(x-2)2+1/2]



Most powers will be automatically recognized by the graph tool.  The graph tool will not automatically recognize powers if


you require a variable as a power
you require a function as a power
you require a power of a number
you require a complicated power.


In these cases you need to explicitly indicate the power using the ^ symbol.  As with fractions, complicated powers need to be surrounded with brackets.  These brackets will not be displayed.



clip0184                        is entered as e^(sinth)

clip0021                        is entered as x^(2y+3)



Spaces change the way a particular equation is formatted and therefore interpreted.  This can best be illustrated using these examples.


clip0022                        is entered as sin2  th

clip0023                        is entered as sin  2th


The only difference between the two equations is the location of a space.