Solve
- To: mathgroup at yoda.physics.unc.edu
- Subject: Solve
- From: vdaele at ieper.lhs.be (Marc Van Daele)
- Date: Tue, 31 Aug 93 09:52:23 +0200
Hi,
I have two quite simple equations which Mma is not able to solve.
Any ideas why?
1)
Solve[{(mu*S0*X0*(1 - y))/y == a0,
(mu^2*S0*X0^2*(-1 + y))/y^2 == a1}, {mu, S0}]
takes indefinetely (at least several hours)
(NextStation)
2)
So I need to help Mma like this:
- first solve S0 from first equation, next replace that solution in second
equation and solve mu from that equation
sol1s0 = Flatten[Simplify[
Solve[(mu*S0*X0*(1 - y))/y == a0, S0]]]
sol1mu = Flatten[Simplify[
Solve[(mu^2*S0*X0^2*(-1 + y))/y^2 == a1 /. sol1s0, mu]]]
sol1s0 = Flatten[Simplify[sol1s0 /. sol1mu]]
Which results in
a1 y
{mu -> -(-----)}
a0 X0
2
a0
{S0 -> ----------}
-a1 + a1 y
3)
Why is this set of equation so difficult for Mma.
And is there an easier way to solve these equations than holding Mma's hands
like this. (I also have a similar problem with six variables)
Thanks for any help,
Marc Van Daele
vdaele at lhs.be