Focus of a Parabola - 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: Focus of a Parabola (/thread-12033.html) Focus of a Parabola - MullenJohn - 12-27-2018 04:57 PM Is there any way to find the focus of a parabola (e.g. 2x^2 -x -1) using the HP Prime. I cannot find a way to do it. If you have found a way please tell me the steps. Cheers! RE: Focus of a Parabola - toshk - 12-27-2018 06:13 PM (12-27-2018 04:57 PM)MullenJohn Wrote:  Is there any way to find the focus of a parabola (e.g. 2x^2 -x -1) using the HP Prime. I cannot find a way to do it. If you have found a way please tell me the steps. Cheers! http://www.hpmuseum.org/forum/thread-10605.html Conics(y-(2*x^2-x-1)) RE: Focus of a Parabola - MullenJohn - 12-27-2018 06:34 PM Thank You Toshk. I was looking for a built-in HP Prime function like something under Catlg or CAS, et cetera. Is there anything like finding the focus with a built-in HP Prime function? Cheers! RE: Focus of a Parabola - toshk - 12-27-2018 06:37 PM (12-27-2018 06:34 PM)MullenJohn Wrote:  Thank You Toshk. I was looking for a built-in HP Prime function like something under Catlg or CAS, et cetera. Is there anything like finding the focus with a built-in HP Prime function? Cheers! reduced_conic(y-(2*x^2-x-1)) RE: Focus of a Parabola - MullenJohn - 12-28-2018 02:37 PM Thank you Toshk. I was unaware of the function reduced_conic(). I was unable to determine from the results of reduced_conic(y-(2x^2+3x+1)) which item would tell me the focus (-3/4, 3/8) or the focal length (p = 1/8). Which part of the result states the focus coordinates or the focal length p = 1/4a? Cheers!