-2
$\begingroup$

I am trying to solve this equation:

1/s^3 + 3s^2 + 4s + 1

But I am not able to solve it. A little help would be appreciated.

P.S: I am new to Mathematica and I am having difficulty with its syntax. If you correct the power then please comment that how to write it.

Improve this question
$\endgroup$
9
  • 2
    $\begingroup$ This actually is fifth order equation, which typically do not have closed form solutions. Use Solve or NSolve. $\endgroup$
    – bbgodfrey
    Commented Apr 21, 2015 at 14:33
  • $\begingroup$ Welcome to Mathematica.SE! I suggest that: 1) You take the introductory Tour now! 2) When you see good questions and answers, vote them up by clicking the gray triangles, because the credibility of the system is based on the reputation gained by users sharing their knowledge. Also, please remember to accept the answer, if any, that solves your problem, by clicking the checkmark sign! 3) As you receive help, try to give it too, by answering questions in your area of expertise. $\endgroup$
    – bbgodfrey
    Commented Apr 21, 2015 at 14:33
  • 4
    $\begingroup$ There is no equation. Back to elementary school! $\endgroup$
    – Artes
    Commented Apr 21, 2015 at 14:34
  • $\begingroup$ What have you tried? Have you tried searching the web about solving equations with Mathematica? $\endgroup$
    – Szabolcs
    Commented Apr 21, 2015 at 14:34
  • $\begingroup$ I have tried by making pairs, adding and subtracting and........ all the methods which can be done by hand. :) @bbgodfrey Thanks for your reply. Next time you will see the change :) $\endgroup$
    – Awais Hussain
    Commented Apr 21, 2015 at 15:05

1 Answer 1

Reset to default
2
$\begingroup$

Perhaps

eq1 = 1/s^3 + 3 s^2 + 4 s + 1 == 0;
eq2 = Simplify[s^3 # & /@ eq1]

1 + s^3 + 4 s^4 + 3 s^5 == 0

which demonstrates that the equation is indeed of the 5th order.

Solve[eq2, s] // N

{{s -> -1.21261}, {s -> -0.506962 - 0.665378 I}, {s -> -0.506962 + 0.665378 I}, 
 {s -> 0.446601 - 0.439765 I}, {s -> 0.446601 + 0.439765 I}}

Edit

I note that, if one is using the Suggestion Bar, then evaluating

 1/s^3 + 3 s^2 + 4 s + 1 == 0

will return

output

Clicking on the 'solve for [s]' suggestion produces

solution

so this can be quite easy even for beginners.

Improve this answer
$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.