# 2equations, 2 Variables

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### #1 uterrorista

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Posted 05 December 2006 - 11:05 PM

i have
(1) Y = 10/25 ( 10 * X - X^2)
(2) 20 = 10 * Y + X
what is the easy way to solve this?

i use the "system" and gives me:
{-0.4 * ( X^2 - 10*X) = Y, 20=X + 10*Y}

i want this (kind of) answer:
(X = 0.44 Λ Y = 1.956) V (X = -5.54 Λ Y = 2.45)

### #2 PAP

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Posted 05 December 2006 - 11:56 PM

This is a nonlinear system. ClassPad's CAS is not able to solve it (unless they added such functionality in OS 3.0, I don't know, since I have OS 2.2). However, you can use my LNA library to solve it easily. Use LNA's function called Broyden; it is able to solve much more complex nonlinear systems than this one .

### #3 vanhoa

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Posted 06 December 2006 - 12:40 AM

OS 3 give me:
{{x=-sqr(361)/8+41/8,y=sqr(1361)/80+119/80},{x=sqr(1361)/8+41/8,y=-sqr(1360)/80+119/80}}

PAP, take a look at my PM

### #4 abelmartin

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Posted 06 December 2006 - 10:28 AM

OS 3.0 don't solve nonlinear systems, but there is an easy way to solve them, then I tell you this way. I'm designing the solution that you can download in PDF. Excuse me for my English.

### #5 vanhoa

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Posted 06 December 2006 - 10:42 AM

WHAT??? OS 3 dont solve nonlinear systems??? How about the result I gave?

### #6 Corteoz

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Posted 06 December 2006 - 01:48 PM

OS 3.0 does solve non-linear systems.

Main -> 2D -> Bottom right icon (curly braces with two boxes)
Each box the the left of the vertical line will hold each equation, then you provide the variables ( x,y ) in the little box to the right of the vertical line.

I get X ~ 0.51 and Y ~ 1.94

### #7 abelmartin

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Posted 06 December 2006 - 05:20 PM

soluci?n en PDF

### #8 uterrorista

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Posted 06 December 2006 - 08:42 PM

where can i get the OS 3.0?? I can't find him in Casio page...

### #9 PAP

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Posted 06 December 2006 - 10:34 PM

where can i get the OS 3.0?? I can't find him in Casio page...

Officially, you have to pay for it. However, you don't really need OS 3 to solve nonlinear systems. I don't have OS 3, so I don't exactly know how capable it is in this case, but I will take the risk to say that, judging from previous releases, I don't think it's better than LNA for solving nonlinear systems .

### #10 uterrorista

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