Solving simulataneous equation using maxima?

Question

Hi I want to solve three equation, please find the details in picture. I want to find the value of alpha, h and Q in terms of alpha and h how do i do this using Maxima?

[B1=\frac{{{h}^{2}}}{\mathit{Qs}}]

[B2={{h}^{2}}+\alpha+1]

[B3=\frac{1}{\mathit{Qs}}]

[B0={{h}^{2}}]

[C2=\frac{{{h}^{4}}}{{{\mathit{Qs}}^{2}}}-2{{h}^{2}}\,\left( {{h}^{2}}+\alpha+1\right) =0]

[C4={{\left( {{h}^{2}}+\alpha+1\right) }^{2}}-\frac{2{{h}^{2}}}{{{\mathit{Qs}}^{2}}}-2{{h}^{2}}=0]

[C6=\frac{1}{{{\mathit{Qs}}^{2}}}-2\left( {{h}^{2}}+\alpha+1\right) =0]

algsys([C2,C4,C6],[h,alpha,Qs]);?????

I'm voting to close this question as off-topic because this is a math problem, not a specific programming problem. — Laurel, Jun 01 '16 at 22:17
@Laurel please look at the linked image and you will see that it is indeed a programming problem. — Robert Dodier, Jun 02 '16 at 00:46
@RobertDodier Well, then you have a different problem. You need to copy and paste the code into the question, not just as a picture. That still makes it off topic, just not in the way I originally thought it was. — Laurel, Jun 02 '16 at 01:07
@Laurel I dunno. It's not really a great idea to jump to a conclusion and then look for a justification after the fact. Maybe if the problem domain is unfamiliar, you could invest more time before making a judgement. — Robert Dodier, Jun 02 '16 at 03:06

score 1 · Answer 1 · answered Jun 02 '16 at 00:59

I see that by just adding QS to the list of variables to solve for, I get some solutions. I didn't check them. Some of them may be redundant, I didn't check that either.

(%i20) algsys ([C2, C4, C6], [h, alpha, QS]);
(%o20) [[h = -1,alpha = -(2^(3/2)-2)/(sqrt(2)-2),QS = sqrt(2-sqrt(2))/2],
    [h = 1,alpha = -(2^(3/2)-2)/(sqrt(2)-2),QS = sqrt(2-sqrt(2))/2],
    [h = -1,alpha = -(2^(3/2)-2)/(sqrt(2)-2),QS = -sqrt(2-sqrt(2))/2],
    [h = 1,alpha = -(2^(3/2)-2)/(sqrt(2)-2),QS = -sqrt(2-sqrt(2))/2],
    [h = -1,alpha = -(2^(3/2)+2)/(sqrt(2)+2),QS = sqrt(sqrt(2)+2)/2],
    [h = 1,alpha = -(2^(3/2)+2)/(sqrt(2)+2),QS = sqrt(sqrt(2)+2)/2],
    [h = -1,alpha = -(2^(3/2)+2)/(sqrt(2)+2),QS = -sqrt(sqrt(2)+2)/2],
    [h = 1,alpha = -(2^(3/2)+2)/(sqrt(2)+2),QS = -sqrt(sqrt(2)+2)/2]]

score 0 · Answer 2 · answered Jun 01 '16 at 22:02

Try replacing h^2 with a single variable, say h2 (and replace h^4 with h2^2).

Try simplifying the equations with expand and/or ratsimp.

In solve(eqns, vars), the variables vars are the ones you are trying to solve for. So I think you want alpha, h, Q (well, actually alpha, h2, Q if you follow my previous advice).

Finally, PLEASE paste your input and output into the question instead of linking to an image, which makes it much more difficult for someone else to try working with your equations.

Thank you for your reply i am getting the same redundant solution after using ratsimp and changing h^2 to h2 — ezE, Jun 03 '16 at 08:03

Solving simulataneous equation using maxima?

2 Answers2