# Mathematica unable to solve equation numerically while Wolfram|Alpha can

I want to solve the following equation

2 x == Sinh[x]


Mathematica is unable to do so

In:= Solve[2 x == Sinh[x], x]
During evaluation of In:= Solve::nsmet: This system cannot be solved with the methods available to Solve. >>
Out= Solve[2 x == Sinh[x], x]


However, Wolfram|Alpha can successfully solve the equation How can I achieve the same in Mathematica?

• Try Solve[2 x == Sinh[x], x, Reals]. This is a common question - here's a similar example. – Mark McClure Jul 21 '14 at 23:46
• You didn't ask Mathematica for a numerical solution, you asked for a symbolic one. – m_goldberg Jul 21 '14 at 23:53
• If I ask Mathematica for a numerical solution, using NSolve, it gives me the same error, though. – Gregger Jul 21 '14 at 23:55
• @Sven86, Use NSolve[2 x == Sinh[x], x, Reals]. NSolve has a default domain of Complexes just like Solve. – Chip Hurst Jul 22 '14 at 0:43

Plot[2 x - Sinh[x], {x, -Pi, Pi}] FindRoot[2 x == Sinh[x], {x, #}] & /@ {-2, 0, 2}

• @Sven86 This syntax also works, though I believe it is undocumented: FindRoot[2 x == Sinh[x], {x, {-2, 0, 2}}]. Note that the output form is different: {x -> {-2.17732, 0., 2.17732}}. – Mr.Wizard Jul 22 '14 at 17:33