Differences between the different solve/zeros commands? - 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: Differences between the different solve/zeros commands? (/thread-2328.html) Differences between the different solve/zeros commands? - pr0 - 10-23-2014 11:36 PM What are the differences between the different solve/zeros commands and which commands are recommended when? Trying to solve this for x but cant find a working command: ARG((-e^(-0.3*i*x))/(x^2-i*x))=-165 Any help would be really appreciated! RE: Differences between the different solve/zeros commands? - Don Shepherd - 10-24-2014 01:05 AM (10-23-2014 11:36 PM)pr0 Wrote:  What are the differences between the different solve/zeros commands and which commands are recommended when? Trying to solve this for x but cant find a working command: ARG((-e^(-0.3*i*x))/(x^2-i*x))=-165 Any help would be really appreciated! What calculator? RE: Differences between the different solve/zeros commands? - rkf - 10-24-2014 06:18 AM (10-24-2014 01:05 AM)Don Shepherd Wrote:  ... What calculator? Since this forum is named "HP Prime", the HP Prime? RE: Differences between the different solve/zeros commands? - parisse - 10-24-2014 08:04 AM This equation has no solution. If you take exp(0.3*i*x), x must be in radians, therefore argument should be rescaled in -pi..pi. fsolve(arg((-e^(-0.3*i*x))/(x^2-i*x))=-165*pi/180,x=-10..10) returns 2 solutions. RE: Differences between the different solve/zeros commands? - pr0 - 10-25-2014 10:01 PM (10-24-2014 08:04 AM)parisse Wrote:  This equation has no solution. If you take exp(0.3*i*x), x must be in radians, therefore argument should be rescaled in -pi..pi. fsolve(arg((-e^(-0.3*i*x))/(x^2-i*x))=-165*pi/180,x=-10..10) returns 2 solutions. Thanks! When is fsolve recommended and when is other commands recommended for solving? Any other cases radians must be selected? RE: Differences between the different solve/zeros commands? - parisse - 10-26-2014 07:34 AM fsolve is recommended if you want a numeric answer, solve if you want a symbolic answer (but solve can only find roots for polynomial-like equations).