Trying Wolfram 14.3. It was with great surprise I saw the engine cannot symbolically handle Sum with a symbolic upper limit. I’m copying here the response I got from GPT-5. The key beyond this simple case is that I would like a symbolic solution without assuming anything about the format of the expression. Has anyone stumbled on this and successfully overcome it? Solving a Summation Equation for $u$ in $q(u)$ (Wolfram 14.3) Problem Overview We have a function defined by a summation: $q(u)=\...
