Repeated root calculation

[Spectre]

Good Morning,

I have used a very simple program in Mathcad 14 to provide the roots of the intersection of tan(L*0.0127) and L*11.1/66680. An image of the program and reaults is posted. It correctly calculates the first 44 roots and then provides incorrect values for the next few (which causes issues in the series summation...) The guesses I have put in for L are the locations of tan(n/L) = 0.0.

I modified the guess ranges several times with no luck, the errors for the higher roots remain...

Any Ideas?

Thank you very much,

H

[AlanStevens · Accepted solution]

The initial guesses become too far out by the time you get to the 45th root. See attached for better approach.

Alan

Edited to attach a slightly improved file.

[Spectre]

Genius!!!

Pure Genius!!!

Thank you very much,

I did not think of solving it that way...

[AlanStevens]

Spectre wrote:

Genius!!!

Pure Genius!!!

Thank you very much,

I did not think of solving it that way...

For "Genius" read "Experience".

Alan