12 replies to this topic

[aero91]

Hi guys!
I'm seeking for help...I've got fx-570ES PLUS and I have to solve a system of linear equations in 3 variables but my calculator is driving me crazy bacause of messages of matherror.
To calculate the eigenvalues of an inertia tensor I have to solve a system of three linear equations in three variables, with the constant terms all zero. Seeing the messages of error every time I try to solve one, I've started to think that the program uses an algorithm based on A^-1*B = X (X vector of solutions, A matrix of the coefficients of the variables, B the vector of the constant terms), This way the message of solution (0,0,0) would be appropriate (it is always a solution in this cases, but not the one I need!) but most of the times the answer I get is an error.
So, what I'm asking you is if someone knows if this could be a matter of:
- limits of the software
- limits of the user
- if someone can figure out an escamotage to solve the problem anyway with a specific procedure. Solving it manually during an exam could really be a loss of time, it would be useful if I could make the machine do it for me

[Forty-Two]

- limits of the user

Idiocy.

[aero91]

Idiocy.

If you could be so kind to explain to me the idiocy of what i wrote, I'm here to listen

[Forty-Two]

If you could be so kind to explain to me the idiocy of what i wrote, I'm here to listen

Nothing. I just couldn't resist. (Though there is some stuff that makes you look unintelligent; mostly the repetition and the lack of clarity)

[flyingfisch]

Nothing. I just couldn't resist. (Though there is some stuff that makes you look unintelligent; mostly the repetition and the lack of clarity)

I think you were a little too harsh there, but whatever.

[aero91]

Nothing. I just couldn't resist. (Though there is some stuff that makes you look unintelligent; mostly the repetition and the lack of clarity)

The first line of my post is called introduction, if you are referring to that as being repetitive.
I'm here with a question. I just use calculators, I don't know the algorithm they use, but I need to know if my Casio can do what I need it to do or not. Of course you can see lacks of clarity. If you can help, I would appreciate that. Ask me questions so I can explain in a more clear way the problem. If you don't, too bad. Anyway, if you really can't stay polite, avoid answering.
Anyway,I made a mistake writing the post, I wrote eigenvalues in place of eigenvectors. My apologize. But I don't know your competences, so you might not even have noticed that.

[flyingfisch]

The first line of my post is called introduction, if you are referring to that as being repetitive.
I'm here with a question. I just use calculators, I don't know the algorithm they use, but I need to know if my Casio can do what I need it to do or not. Of course you can see lacks of clarity. If you can help, I would appreciate that. Ask me questions so I can explain in a more clear way the problem. If you don't, too bad. Anyway, if you really can't stay polite, avoid answering.
Anyway,I made a mistake writing the post, I wrote eigenvalues in place of eigenvectors. My apologize. But I don't know your competences, so you might not even have noticed that.

I dont know about your calculator, but I think the FX-9860 can do both eigenvalues and eigenvectors.

[MicroPro]

Hi! Back to your problem, the answer to a system of equations with constants being all zero will likely be undefined. What method are you using for calculating eigenvectors? Are you sure it's correct?

[E000N]

I don`t know your region. Maybe a fx991es or 115es can solve it as it has eqn function.

[flyingfisch]

Hello E000N and welcome to UCF! You should introduce yourself.

Would you mind elaborating? because I dont think either calc can do it because of what MicroPro said.

Hi! Back to your problem, the answer to a system of equations with constants being all zero will likely be undefined. What method are you using for calculating eigenvectors? Are you sure it's correct?

[E000N]

Hello E000N and welcome to UCF! You should introduce yourself.

Would you mind elaborating? because I dont think either calc can do it because of what MicroPro said.

OK. I think if there is no situation like all zero. eqn can be used to solve 3 linear equations in 3 variables. What we need to do is to fill in the blanks like this "anx+bny+cnz=dn" (x,y,z are variables) Also solution like all aero may be easily solve by ourselves.(just let x,y,z =0,and see if left = right) Excuse me for my English.

Edited by Forty-Two, 02 February 2013 - 01:03 AM.
please don't change colors mid-paragraph

[flyingfisch]

OK. I think if there is no situation like all zero. eqn can be used to solve 3 linear equations in 3 variables. What we need to do is to fill in the blanks like this "anx+bny+cnz=dn" (x,y,z are variables) Also solution like all aero may be easily solve by ourselves.(just let x,y,z =0,and see if left = right) Excuse me for my English.

Ah, ok, so using the polynomial solver? (at least I think that's what its called on the fx9860)

[E000N]

Ah, ok, so using the polynomial solver? (at least I think that's what its called on the fx9860)

Right, On casio`s science caculater, it calls EQN.