Hello, i have problem, can someone help me with PTC Mathcad Prime 11.0.0.0?

Hi,

please upload your mcdx file.

Your problem is caused by trying to plot a (2-column) vector Y against a range variable (X).  You need to make both expressions in a 2D plot vectors or have the y-expression dependent upon X. 

However, in your case, there is no need for X.  rkfixed returns a 2-column vector, the first column of which is the list of x-coordinates and the second the y-coordinates (ie, solution to the DE).   So, simply use the Mathcad column operator to extract and plot them both.

What version of Mathcad Prime are you using?

Stuart

Hi @DV_13990037,

I wanted to see if you got the help you needed.

If so, please mark the appropriate reply as the Accepted Solution. It will help other members who may have the same question.
Of course, if you have more to share on your issue, please pursue the conversation. 

Thanks,
Anurag