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Solve[] with inequalities

• To: mathgroup at smc.vnet.net
• Subject: [mg121991] Solve[] with inequalities
• From: enis <eniskayis at hotmail.com>
• Date: Sat, 8 Oct 2011 05:33:35 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com

I have the following problem parameters:

cl1 = 0.2; ch1 = 0.7; m1 = 0.65;
cl2 = 0.4; ch2 = 0.5; m2 = 0.3;

When I use the call

In[90]:= Solve[{D[(a - (w1 + ch2))^2/(4 b) (w1 - cl1)^2/((ch1 - cl1)
(m1 - cl1)) ((ch2 - cl2)/(ch2 - cl2)), w1] == 0 && w1 > 0.2}, {w1},
Reals, VerifySolutions -> True]

I get
Out[90]= {{w1 -> 0.5}}

But when I use the call

In[91]:= Solve[{D[(a - (w1 + ch2))^2/(4 b) (w1 - cl1)^2/((ch1 - cl1)
(m1 - cl1)) ((ch2 - cl2)/(ch2 - cl2)), w1] == 0 && w1 > 0.0}, {w1},
Reals, VerifySolutions -> True]

I get
Out[91]= {{w1 -> 0.2}, {w1 -> 0.35}, {w1 -> 0.5}}

Clearly, 0.3 is a solution to the first call, but it disappears in the
first call. Any ideas why? Is this a bug in the code?

Thanks,

Enis.

• Follow-Ups:
  • Re: Solve[] with inequalities
    • From: DrMajorBob <btreat1@austin.rr.com>