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17-Peridot
December 19, 2018
Solved

FIND issue

  • December 19, 2018
  • 1 reply
  • 1941 views

Hello,

 

can anybody help me to find out why this FIND doesn't work?

 

Raiko

Best answer by Werner_E

You have not defined theta and delta.

theta does not depend on rho1, so you can calculate it directly in front of the solve block.

You then have to provide a guess for delta and let the solve block solve for delta, too.

As delta and rho are of different dimensions you have to assign the result of find to a 2x1 vector as Mathcad can't display arrays with elements of different dimensions (in your case kg/m^3 and unitless).

B.png

1 reply

Werner_E25-Diamond IAnswer
25-Diamond I
December 19, 2018

You have not defined theta and delta.

theta does not depend on rho1, so you can calculate it directly in front of the solve block.

You then have to provide a guess for delta and let the solve block solve for delta, too.

As delta and rho are of different dimensions you have to assign the result of find to a 2x1 vector as Mathcad can't display arrays with elements of different dimensions (in your case kg/m^3 and unitless).

B.png

Raiko17-PeridotAuthor
17-Peridot
December 19, 2018

Thank you Werner.

 

However, the solution can't be right as it returns a negative density. When I try to force it to be positive by using rho1 > 0 and delta > 0 then the solve block doesn't converge. any idea how to remedy this?

 

Raiko