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1-Visitor
February 20, 2026
Solved

Issue with Solve Block in Mathcad Prime 9

  • February 20, 2026
  • 1 reply
  • 141 views

I was trying to convert a mathcad 15 file to mathcad prime 9, but I get an error in solving for this variable I placed all my guess values and constraints but it still does not work. Refer to the pictures with the solve block and how it was performed in mathcad 15.Mathcad 15 how it was performedMathcad 15 how it was performedMathcad prime 9.0 error in solve blockMathcad prime 9.0 error in solve block

 
Best answer by Werner_E

Main problem was that you used a literal index on xi while you should have used a vector matrix index.

grafik.png

 

Another problem was an error in the second solve block equation of the first solve block.

 

Details see in attached Prime 9 file

1 reply

25-Diamond I
February 20, 2026

I guess you can spot the difference

grafik.png     grafik.png 

can't you?

 

You have a system of three equations and three variables you provide guess values for. 

So you also have to solve for all these three variables, not just for one!

Otherwise Prime would use the guess values for x.na and fc and tries to find a solution for fs which fulfills all three equations and obviously can't find such a solution.

1-Visitor
February 20, 2026

I originally performed it the way that you are telling me but, refer to the photo below, I got the same error and from videos that I saw I believed this was the correct way to solve in prime.

Mathcad Prime Error2.png

 
25-Diamond I
February 20, 2026

 

You may try to assign CTOL a larger value to increase the chance that the integrals converge.

Setting it to a smaller (10^-7) value than 10^-3 as you did decreases the chance.

 

So why don't you attach both sheets here, the MC15 and the P9 sheet.

Depending on the way you attach and the browser you use you may need to pack them into a zip archive to be allowed to attach them.