2 variables in 2 quadratic equations in excel

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fsshl

Dear ms excel user/programmers:

I hope this question is not repeated before. But anyway

highly appreciate anyone can tell me how (or hint) to use ms excell
and/or visual c/c++, basic, or octave(emulate matlab) to solve:
(12-x)^2 + y^2 =15^2,
(16+y)^2+x^2=25^2

(by programming or using its built in function)?

that ^2 mean square.

looking to any excel user, mathmatician, and/or programmer's help,
eric, (e-mail address removed)
 
Hi Eric

The brute force way (requiring the least mathematical analysis) is to
calculate the left hand side as functions of two reasonable first guess x
and y inputs and then calculate the total error (say as a sum squares of the
differences) of these compared to the right hand sides.

Once you have that you can run the solver add-in to minimise (or set to
zero) the error cell's value by altering (subject to optional constraints)
your input x and y values.

Regards

Steve Dalton
 
and/or ...octave(emulate matlab) to solve:

I don't have matlab, but I would assume there is a Solve command similar to
the following.
Are you looking for a more general form of the equation in order to solve
other equations with different variables?

equ =
{
(12-x)^2 + y^2==15^2,
(16+y)^2 + x^2==25^2
};

Solve[equ]

{x -> 0, y -> 9},
{x -> 24, y -> -9}

HTH
 
Just be advised that, in general, two circles may not intersect (two
imaginary solutions), have 1 common point, or hopefully in your example, two
real solutions...

http://mathworld.wolfram.com/Circle-CircleIntersection.html

HTH
--
Dana DeLouis
Win XP & Office 2003


Dana DeLouis said:
and/or ...octave(emulate matlab) to solve:

I don't have matlab, but I would assume there is a Solve command similar
to the following.
Are you looking for a more general form of the equation in order to solve
other equations with different variables?

equ =
{
(12-x)^2 + y^2==15^2,
(16+y)^2 + x^2==25^2
};

Solve[equ]

{x -> 0, y -> 9},
{x -> 24, y -> -9}

HTH
--
Dana DeLouis
Win XP & Office 2003


Dear ms excel user/programmers:

I hope this question is not repeated before. But anyway

highly appreciate anyone can tell me how (or hint) to use ms excell
and/or visual c/c++, basic, or octave(emulate matlab) to solve:
(12-x)^2 + y^2 =15^2,
(16+y)^2+x^2=25^2

(by programming or using its built in function)?

that ^2 mean square.

looking to any excel user, mathmatician, and/or programmer's help,
eric, (e-mail address removed)
 

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