Solved: Equation Solving.

lvl107 · ‎Dec 12, 2012

Hello, Everyone.

Regards.

Werner_E · ‎Dec 16, 2012

Did you look at Valerys post? It seems that Mathcad is not good at solving diophantic equations and so all I can think of is to try it with brute force like Valery had shown. Look at the attached. It seems that there are quite some solutions for X=100. Calculation time quickly grows if you increase the endvalues for X and Y (the parameters of the function Sol). As you can see in the screenshotmy machine is rather slow 😉 So good luck and patience.

WE

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ValeryOchkov · ‎Dec 12, 2012

It is one solution in/for Mathcad - in/for an engeneering office Or you would like to have one integer solution!?

Werner_E · ‎Dec 12, 2012

One set of integer solution seems to be 7722793 / 197 / 1 for X / Y / Z.

But Mathcad's Find seems not to be able to find it using constraints like X=trunc(X), etc.

Strange effect with symbolic evaluation without guess values. Why does MC solve for Y?

lvl107 · ‎Dec 12, 2012

Many thanks for your help, Werner and Valery. And I have a related question :

Regards.

ValeryOchkov · ‎Dec 13, 2012

One more simple integer task for some meditation:

ValeryOchkov · ‎Dec 13, 2012

One more old problem:

A smith had 8 pieces of copper, each weighing 1 pound and 8 spools. This smith made from this copper 6 kettles whith weighing 1 pound, 21 lots and 1 spool. How many lots is in one pound and how many spools is in one lot? Do you know old russian weight units - pound, lot and spool?

I've seen this problem with the answer in one old book. I could search in internet old Russian pound, lot and spool. But I found the answer by using Mathcad! Can you do it?

I think there is a lot of same task with old english/US units of mass, weight and money.

lvl107 · ‎Dec 13, 2012

And I need help with a brief explanation for the following :

Regards.

lvl107 · ‎Dec 16, 2012

Hello again, and I have a related question :

and with my solution ( attachment ) is still a cheating-guess way. And I really need help with another way.

Regards.

Werner_E · ‎Dec 16, 2012

Did you look at Valerys post? It seems that Mathcad is not good at solving diophantic equations and so all I can think of is to try it with brute force like Valery had shown. Look at the attached. It seems that there are quite some solutions for X=100. Calculation time quickly grows if you increase the endvalues for X and Y (the parameters of the function Sol). As you can see in the screenshotmy machine is rather slow 😉 So good luck and patience.

WE

ValeryOchkov · ‎Dec 16, 2012

Werner Exinger wrote:
Did you look at Valerys post?

Do you know than a+b sometime is not equel b+a - in Numeric and symbolic Math

See please http://communities.ptc.com/groups/mathcad-paradoxes