Where can I calculate the exponential of a matrix online? Where can I exponentiate a $3\times 3$ matrix like $\left[\begin{array}{ccc}
0 & 1 & 0\\
1 & 0 & 0\\
0 & 0 & 0
\end{array}\right]$
  online?
Is there some website where this is possible?
Thank you very much.
 A: Somewhat perversely, could I suggest you first try analytically, by Sylvester's formula, or, more specifically, simpler methods as below? 
Still, in your specific case, this would be overkill: your matrix is trivially diagonalizable,
$$M=\left[\begin{array}{ccc}
0 & 1 & 0\\
1 & 0 & 0\\
0 & 0 & 0
\end{array}\right]=\frac{1}{\sqrt2}\left[\begin{array}{ccc}
1 & 1 & 0\\
1 & -1 & 0\\
0 & 0 &  {\sqrt2}
\end{array}\right] ~~
\left[\begin{array}{ccc}
1 & 0 & 0\\
0 & -1 & 0\\
0 & 0 & 0
\end{array}\right]~\frac{1}{\sqrt2}\left[\begin{array}{ccc}
1 & 1 & 0\\
1 & -1 & 0\\
0 & 0 &  {\sqrt2}
\end{array}\right]\equiv R^{-1} D R,$$
for the obviously defined diagonal matrix D and diagonalizing rotations R.
It then immediately follows that 
$$
\exp M= R^{-1} e^D R=  \left[\begin{array}{ccc}
\cosh 1 & \sinh 1 & 0\\
\sinh 1 & \cosh 1 & 0\\
0 & 0 & 1
\end{array}\right].
$$
Sylvester's formula generalizes to non-diagonalizable matrices, but my sense is you are dealing with diagonalizable ones.
A: Depending on which matrix exponential you want, you can use:


*

*Wolfram Alpha 1st option: $e^{A}$

*Wolfram Alpha 2nd option: $e^{At}$
This is actually a command in Mathematica.
I would be surprised if were not available in other CAS programs and some of those are online, like Sage, Maxima and others.
