discriminant of a quadratic

[Sheila]

Hi
I'm trying to write a program that will find the discriminant and
display the nature of the solutions. I know how to begin but get lost
when trying to write the "when" or if statements...If you have a file
that is great I can look at that but I would also like to know what to
do.
thanks,
Sheila

[Andy Kemp]

Sheila,

I'm not sure I completely understand what you want to do, are you trying to write a function for the calculator page like:
disc("x^2+3x+2")

Are you doing this on the CAS or non-CAS version?

I wrote something a while ago which calculated the discriminant of a quadratic on the G&G page and allowed you to drag the graph around and observe the effect on the discriminant... 

You can find it attached - it is designed to be viewed on the handheld

Cheers
Andy

[Sheila]

very nice file..I like the diagram and ideas....what I want to do is
write a program(function) that will give the discriminant (I can do
this) but then also state whether there is 1 real, two real, two
complex conjugates based on the result. I know I can do it with when
statements but I'm not sure how to write it into the program.

>  Discriminant.tns
> 8KViewDownload- Hide quoted text -
>
> - Show quoted text -

[Steve Arnold]

This should fit the bill Sheila:

Define LibPub discr(a,b,c)=
Func
:Local d,eq
:d:=b^(2)-4*a*c
:eq:=string(a)&"x²+"&string(b)&"x+"&string(c)
:Disp "The discriminant of ",eq," is ",d
:If d=0 Then
:Disp "This is a perfect square with two equal solutions"
:ElseIf d>0 Then
:Disp "Two distinct real solutions"
:Else
:Disp "No real solutions"
:EndIf
:Return d
:EndFunc

Hope this helps

Steve

With best wishes,
Steve
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Compass Learning Technologies

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