Arbitrary constants

Forum Attachments

Arbitrary constants

ahmed777 28 Nov 2012 04:27

Hi,
I'm currently working on a program that does lagrange multipliers, minimizing and maximizing a function given n number of constraints. The problem is that in order for it work, I need to create a system of equations and solve for n number of constants, is there a way to do that with the ti-89? Currently I have split this into multiple programs, one for one constraint (and therefore one constant), one for two constraints and so on but I'd like to make it more efficient. Any help is much appreciated.
Thanks,
Ahmed

Re: Arbitrary constants

Xeda Elnara 28 Nov 2012 13:13

First, I have a question: Have you gotten to take Linear Algebra yet? If not, it is some fun stuff that can help you with these kinds of problems :D Basically, make a matrix using the coefficients of your system of equations. For example:

2x+3y=4
3x+y=5

This would turn in to:

[[2 3 4
  3 1 5]]

Now you just find the reduced row echelon form of the matrix using the command rref() and it will give you the following:

[[1 0 11/7
  0 1 2/7]]

What that tells you is that your first variable ('x' in this case) is 11/7 to solve the system and y=2/7.

I hope that helps! By the way, this works for larger matrices, to. On the calc, it looks like this:

rref([[2,3,4][3,1,5]])

Unfortunately, the rref() command has yet to be filled in for the 68k calcs, but it is basically the same syntax as for the TI-83+/84+ calcs, so here is a link: rref(

---

Z80 Assembly>English>TI-BASIC>Python>French>C>0