0
$\begingroup$

I have this simple equation to solve (1 == 62.5*E^(-30*10^6/x), {x}), and Mathematica is able to give a correct answer. However, there is this warning message (warning message) I don't understand, can anyone elaborate what this message means?

$\endgroup$
1
$\begingroup$

There are many complex-valued solutions; Mathematica gives you the unique real-valued one here but warns you about the loss of generality. If you want all solutions, try

Reduce[1 == 125/2*E^(-30*10^6/x), x]
$\endgroup$
  • 1
    $\begingroup$ Or Solve[1 == 125/2*E^(-30*10^6/x), x, Method -> Reduce] $\endgroup$ – Bob Hanlon Jan 10 at 19:30
  • $\begingroup$ Thanks! Both methods work well. $\endgroup$ – baker Jan 14 at 13:33
0
$\begingroup$

Tell Mathematica that you search for a real solution:

Solve[1 == 125/2*E^(-30*10^6/x), x, Reals]
(*{{x -> -(30000000/(Log[2] - 3 Log[5]))}}*)
$\endgroup$
  • $\begingroup$ Thanks, I do only need reals, great suggestion. $\endgroup$ – baker Jan 14 at 13:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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