Easy question about System of equations solver
04-29-2016, 07:54 AM (This post was last modified: 04-29-2016 07:57 AM by PedroML.)
Post: #1
 PedroML Junior Member Posts: 5 Joined: Apr 2016
Easy question about System of equations solver
Hello, here a newbie using HP Prime, Thank you for your attention.

As I am using solve() for getting the solutions of a simple polynomical system, it provides 2 pairs of solutions. The question is, how can I store each of them wihtout retyping?.

Maybe the attached screenshot will help to understand the question.
ScreenShot

Pedro ML

Attached File(s) Thumbnail(s)

04-29-2016, 08:01 AM
Post: #2
 primer Member Posts: 135 Joined: Sep 2015
RE: Easy question about System of equations solver
you can copy the list to a variable,
Code:
Ans▶L1
and then ask for 1st solution :
Code:
L1(1)
and for the 2nd :
Code:
L1(2)

primer
04-29-2016, 09:32 AM
Post: #3
 DrD Senior Member Posts: 1,101 Joined: Feb 2014
RE: Easy question about System of equations solver
This also works:

L1:=solve({2*x^2+3*y^2 = 1, 2*x+3*y = 1},{x,y})

L1(1) ==> [-0.29 0.53]
L1(2) ==> [ 0.69 -0.13]]
04-29-2016, 09:49 AM
Post: #4
 PedroML Junior Member Posts: 5 Joined: Apr 2016
RE: Easy question about System of equations solver
I see, thank you!
As L1 is a list and elements are matrix 1x2, then I need:
L1(1)▶M1
L1(2)▶M2
and I can use M1(1,1), M1(1,2), M2(1,1), M2(1,2)

Is that right?
04-29-2016, 10:04 AM (This post was last modified: 04-29-2016 10:39 AM by DrD.)
Post: #5
 DrD Senior Member Posts: 1,101 Joined: Feb 2014
RE: Easy question about System of equations solver
(04-29-2016 09:49 AM)PedroML Wrote:  I see, thank you!
As L1 is a list and elements are matrix 1x2, then I need:
L1(1)▶M1
L1(2)▶M2
and I can use M1(1,1), M1(1,2), M2(1,1), M2(1,2)

Is that right?

M1 is a vector in this case, with size(M1) == 2. So elements of the vector are:

M1(1) == -0.29
M1(2) == 0.53

M2(1) == 0.69
M2(2) == -0.13

When:
L1:={[-0.29 0.53], [0.69 -0.13]};
L1(1,2) ==> 0.53 (For example, to reach the second element of the first vector, as a one dimensional array, in a list of vectors).

As a vector, there aren't any rows and columns, its just a one dimensional array. M1(row, col) works for matrices. Lists, vectors, and matrices are a subject that could stand additional clarification in the user references. Lists and vectors have a lot in common. The solve() command is one particular example. For instance, if you try the examples given in the calc Help, some return lists, and others return vectors. The Help detail says the command "Returns a list of the solutions..."
04-29-2016, 11:21 AM
Post: #6
 PedroML Junior Member Posts: 5 Joined: Apr 2016
RE: Easy question about System of equations solver
Thank you both, got it!!!