TI Nspire CAS step by step

[justpassingby]

The equations from the video I can solve but the equation that I posted here and similar equations I can't.

And what is the righ syntax on simultstep?

[Bisam]

Well, indeed, we messed up !!

Your equations are NOT linear equations... so they can't be solved with "linsolve" or "simultstep" (unless you change your "y" in "1/t").
You can still use "solve"... but you won't have th steps.

If you change "y" in "1/t", the equations become linear and can be solved with "linsolve" or "simultstep", solving them for "x" and "t" of course !

The syntax for "simultstep" needs you know a little about matrices.
Write your linear system as AX=B where A is a square matrix and B a vector matrix and type "simultstep(A,B)" using the matrices A et B.

For your example :
1) rewrite the system with "t=1/y" :

$mathjax$(E) \; \left\{ \begin{array}{r c l} x&=&\frac{1}{2}(5000\, t-1) \\ x&=&\frac{1}{9}(6000\, t-1) \end{array}\right.$mathjax$

2) make the matrices appear :

$mathjax$(E) \Leftrightarrow \left\{ \begin{array}{r c l} 2\, x-5000\, t&=&-1 \\ 9\, x-6000\, t&=&-1 \end{array}\right. \Leftrightarrow \begin{pmatrix}2&-5000\\9&-6000\end{pmatrix} \begin{pmatrix}x\\t\end{pmatrix}\begin{pmatrix}-1\\-1\end{pmatrix}$mathjax$

3) use the matrices in "simultstep" :

Code: Select all

simultstep([[2,-5000][9,-6000]], [[-1][-1]])

But all this seems a little "overkill" since your system is VERY easy to solve by hand...