Anyone want to try their hand at a nonlinear simultaneous set of equations?

Capn

Platinum Member
Jun 27, 2000
2,716
0
0
#1
It's the off-season and my brain is in storage till september. :)

Anyway, so somebody did a best fit to some data using the equation form of

eta = [C1*x1 + C2*(x2^C3)]^(-1)

So I don't have the values for C1..C3, but need to find them out, but I do have more than three data points with x1, x2, and eta.

Pt 1
eta = 0.322294
X1 = 5.0
X2 = 10.0

Pt 2
eta = 0.123184
X1 = 5.0
X2 = 100.0

Pt 3
eta = 0.001896
X1 = 5.0
X2 = 1000.0

I'm not that great at solving the nonlinear equations anyways, but I'll try again just want somebody to double check my values maybe. This isn't a class assignment or anything.

 

DAM

Diamond Member
Jan 10, 2000
6,103
0
76
#3
x1 = eta^-1 - c2(x2^c3)/c1

x2 = root of c3(eta^-1 - c1*x1/c2)



dam()


edit

ohh crap i just notice a mistake in the above give me a couple of minutes and ill solve them for ya.


dam()

/edit
 

DAM

Diamond Member
Jan 10, 2000
6,103
0
76
#5
actually all you have to do is solve for both then plug them back into the other equation, or use maple or mathematica to solve the equation for all possible solutions.


dam()
 

Capn

Platinum Member
Jun 27, 2000
2,716
0
0
#6
I didn't have maple available to me when i was at work, but now I can telnet in to my school and use it.
 

DAM

Diamond Member
Jan 10, 2000
6,103
0
76
#8
wait but i though it the question was "how many roads must a man walk?"



dam(HHGTTG)
 

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