Solve a system of nonlinear equations

solve

asked 2015-05-06 20:26:34 +0100

Massimo2013
71 ●4 ●6 ●10

I'm trying to solve the following system of nonlinear equation:

var("x,L,a")
sms = (x/(1-L))^(1-a) == .3
bb = x == .3*L
solve([sms,bb],x,L)

I expect that sage gives me a symbolic solution, the output is the following:

[x == 0.3*L, (-x/(L - 1))^(-a + 1) == 0.3]

As I am a newbie to sage, I wonder if there's something wrong/missing

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answered 2015-05-07 03:55:39 +0100

calc314
4191 ●22 ●48 ●113

Since bb is fairly simple, you can substitute that into sms. Then, solving gives something nice. However, you have to tell Sage some information about a.

var("x,L,a")
assume(a>0)
assume(a<1)
sms = (x/(1-L))^(1-a) == 3/10
bb = x == 3/10*L
solve(sms.subs(bb),L)

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Comments

I have a similar problem where my version of bb is not so simple and (sms == sms.subs(bb)) is true. Does a different method exist to solve the problem?

Johan ( 2016-05-18 15:08:39 +0100 )edit

I suggest creating a separate post and giving some example code so we can see exactly what you are working with.

calc314 ( 2016-05-18 22:15:41 +0100 )edit

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Asked: 2015-05-06 20:26:34 +0100

Seen: 828 times

Last updated: May 07 '15

Solve a system of nonlinear equations edit