Step by step



It doesn't really matter, but by using the simpfuncs option, the square root can be
denested by the solver:

(%i3) (load(to_poly_solver), load(sqdnst))$

(%i4) %solve(sqrt(3-sqrt(x-1))-sqrt(x-sqrt(2)),x, 'simpfuncs = ['sqrtdenest]);
(%o4) %union([x=3])

--Barton
________________________________
From: maxima-bounces at math.utexas.edu [maxima-bounces at math.utexas.edu] on behalf of Stavros Macrakis [macrakis at alum.mit.edu]
Sent: Monday, August 20, 2012 10:22
To: Igor
Cc: maxima at math.utexas.edu
Subject: Re: [Maxima] Step by step

The solve command doesn't handle cases like this, but %solve does:

load(to_poly_solve)$
eq: sqrt(3-sqrt(x-1))-sqrt(x-sqrt(2))$
sols: %solve(eq,x);
sol: part(sols,1,1,2)   <<< extract the one solution from the Union expression

sol =>
     -(sqrt(2^(5/2)+9)-2^(3/2)-7)/2

Messy, eh?  float(sol) seems to be equal to 3. None of Maxima's standard simplifiers (ratsimp, radcan) can reduce this to 3, but Maxima does have a special simplifier for square root denesting:

load(sqdnst)$
sqrtdenest(sol) => 3

This doesn't give you a 'step-by-step' solution, though.

I wonder, too, if sqrtdenest shouldn't be either part of the general simplifier or of radcan....

          -s


On Sun, Aug 19, 2012 at 4:37 PM, Igor <igor at iuav.it<mailto:igor at iuav.it>> wrote:
Dear,
Who can help me?
I need a step by step solution of the following equation: sqrt(3-sqrt(x-1))-sqrt(x-sqrt(2)).

The only result I get is the following: sqrt(x-sqrt(2))=sqrt(3-sqrt(x-1)).

Now, how can i get a right result for x by a step by step solution?
Many many thanks.
Igor



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