 HP Prime Solve command at exp-Fkt. often does not work - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: HP Prime Solve command at exp-Fkt. often does not work (/thread-12743.html) HP Prime Solve command at exp-Fkt. often does not work - Retrocomp - 04-05-2019 06:15 PM Hello, I have big problems solving exponential equations in CAS mode with the Solve command. 1 E.g. the equation (x^2-16)*exp(-0,5*x) has x1=4 and x2=-4 as solution. I don't get a solution from Prime. It works very well (x^2-16)exp(x), it even works with a fraction instead of -0,5, but not with -0,5. I have tried a lot and have no idea anymore. What am I doing wrong? best regards Jürgen RE: HP Prime Solve command at exp-Fkt. often does not work - parisse - 04-06-2019 05:31 AM (x^2-16)*exp(-0.5*x) is an approx equation because 0.5 is an approx number, you can solve it with the approx solver: fsolve((x^2-16)*exp(-0.5*x)) If you want to use the exact solver, convert 0.5 to an exact coefficient and run solve: solve((x^2-16)*exp(-1/2*x)) RE: HP Prime Solve command at exp-Fkt. often does not work - Retrocomp - 04-07-2019 09:30 AM Thank you very much for your answer! Yes, fsolve finally solves it, but only under protest with a strange error message. The command Zero again leads to no result. With parameters it gets even worse, example follows... kindly regards