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Re: why is this happening?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg99243] Re: why is this happening?
  • From: dh <dh at metrohm.com>
  • Date: Thu, 30 Apr 2009 06:26:29 -0400 (EDT)
  • References: <gt9aq0$q7o$1@smc.vnet.net>


Hi,

the second equation is NOT a scaled form of the first one, but a 

different.  Perhaps you mean:

ld + k2 + ld^2/k1 == 0

Daniel





sean_incali at yahoo.com wrote:

> Consider the following.

> 

> Solve[k1 ld + k1 k2 + ld^2 == 0, ld]

> 

> vs

> 

> Solve[k2/k1 + ld^2 + ld == 0, ld]

> 

> 

> I expected to get the output I got from the first code.

> 

>>From the second code, I was expecting something along the lines of

> 

> ld ->-1 + (SquareRoot[1 - 4 (k2/k21)])/2

> ld -> -1 - (SquareRoot[1 - 4 (k2/k21)])/2

> 

> since that is the answer.

> 

> Why is Mathematica turning the second scaled equation into the

> unscaled one in the first before solving it?

> 

> Thanks for any insight.

> 

> Sean

> 

> 




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