if function in graph

[sportler1993]

Hello
I search a programm witch can split a graph in 3spaces
Perhaps If X<=2 Y=2X
If 10<X>2 Y=5x
If X>=10 Y=50

Is there any possibility to make this

[Levak]

Hi,
You can directly do it in a function on TI-Nspire :

Code: Tout sélectionner

: Define myfunc(x) = Func
:   If x <= 2
:     Return 2*x
:   If x > 2 and x < 10
:     Return 5*x
:   Return 50
: EndFunc


and draw the function f1(x) = myfunc(x) in a Graph page.

[sportler1993]

Thanks
But i dont know where i should enter this code?
Thanks for help

[Bisam]

You can also use the function "when" or better, the "piecewise template", that is the left bracket { with 4 spaces 2 by 2 separated by commas.

The syntax for the piecewise template is :

Code: Tout sélectionner

{ 2x , x<=2
{ 5x , x>2 and x<10
{ 50 , x>=10

where the left brackets should be only one bracket on you calc.

The one for "when" is :

Code: Tout sélectionner

when(x<=2, 2x, when(x<10, 5x,50))

If you use Levak's method, you should create a "function" using the editor on calc.

[sportler1993]

Whiy this code dont work?
How can i define a?

Code: Tout sélectionner

: Define myfunc(x) = Func
:   a=2x
:   If a <= 2
:     Return 2*x
:   If a > 2 and a < 10
:     Return 5*x
:   Return 50
: EndFunc


[Excale]

a:=2x and Endif .

[Levak]

Hi
You also should use "Local a" at the beginning of the functiin since in a Func (contrary to a Prgm) you cannot modify the external variables.

[Bisam]

The "Endif" is not necessary : there is no "Then".
Is is useless when there is only one instruction after "If".

As for the "Local", you HAVE TO use it in a function.