09-30-2016 03:42 PM
Hi, I'm trying to use the solve function with the next funtion
I dont have the result, unless I change the p variable, In a TI Nspire I have the answer:
Solved! Go to Solution.
10-06-2016 07:03 AM
This seems to be a particularly difficult one to solve, e.g. the 50g quickly decides it can't find a solution (using the ISOL function) and Wolfram Alpha comes up with some horrendous looking solutions (1 real and 2 complex solutions, each several lines long with powers, roots, cube roots & fractional powers).
So kudos to the NSpire for finding a solution (by the way what does that yellow warning triangle mean?)
As a test I tried the simpler equation X^2 - 6*X +7 - P = 0, both the Prime and 50g quickly find the solutions.
10-06-2016 08:17 AM
The yellow exclamation means "this may not be correct over the whole domain"... basically, it gives *a* result but in many cases its made some automatic assumptions that are only valid for a much smaller part of the domain. I've seen it also be just totally wrong as well sometimes.
Although I work for the HP calculator group as a head developer of the HP Prime, the views and opinions I post here are my own.
10-06-2016 10:13 AM - edited 10-06-2016 10:14 AM
You didn't any bug.
Check, with Wolfram Alpha, from ... http://www.wolframalpha.com/input/?i=solve+function(%5Bx%5E2-6x%2B7%2Fx-p%3D0%5D,%5Bx%5D)
Have a nice day !.
@Maké (Technical Advisor Premium - HP Program Top Contributor).
Provost in HP Spanish Public Forum ... https://h30467.www3.hp.com/
10-06-2016 10:48 AM
I saw that before, http://www.wolframalpha.com/input/?i=solve+x%5E2-6x%2B7%2Fx-p%3D0+,x , but I want yo know if this is going to be posible to do in the HP Prime or not, Why Ti can do that at least aprox. forms
10-07-2016 07:15 AM
From what I understand from Tim's answer is that the yellow triangle on the NSpire essentially means "don't trust this answer".
So in my opinion that means with either the Prime or NSpire you are no better off:
"no answer" vs "an answer you can't trust"
10-08-2016 09:02 AM
When you multiply the right and left side with x you get:
This is a cubic equation.
The general solution of a cubic equation is very, very complicated and hardly of any practical significance.
(at least not when you have the disposal of the power of a calculator like this one)
I do not regret at all that the calculator does not use this formula. You can find it at many places on the internet.