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+--- 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).