RE: solving nonlinear equation with mathematica !!

• To: mathgroup at smc.vnet.net
• Subject: [mg47160] RE: [mg47146] solving nonlinear equation with mathematica !!
• From: "David Park" <djmp at earthlink.net>
• Date: Sun, 28 Mar 2004 00:07:49 -0500 (EST)
• Sender: owner-wri-mathgroup at wolfram.com

```The second root looks pretty accurate on my plot.

Needs["Graphics`ImplicitPlot`"]

ImplicitPlot[{x^2 - y - 1 == 0, 10x Exp[-x] - y == 0}, {x, 1.8, 2.1}, {y, 2,
3.5},
AspectRatio -> 1,
Frame -> True,
Axes -> False];

David Park

From: why [mailto:m004202002 at yahoo.com]
To: mathgroup at smc.vnet.net

Hi,

I face root finding problem solving nonlinear equation

I have system nonlinear equation

x^2-y-1 = 0;
10x exp(-x)-y = 0 ;

If you draw the graph you see two intersecting point .

I have found a point [Using FindRoot function ]
In (-0.1,-0.5) the point is (-0.0905897,-0.991794 )---it is OK

But
In (2.0,1.0) the point is (1.94463,2.7816)
But the graph says the x->2.something ,y->1.somthing
I have used same FindRoot function to find the root
in (2.0,1.0 ).

..
I want(exam)to use other methods(bisection/secant etc).
If any one have workout examples of nonlinear equation