How to divide by a matrix I found a question in an old exam, where the function $\phi(z) := \frac{\exp(z) - 1}{z}$ is given. 
Now we evaluate $\phi(\mathbf{A})$. But how do I divide by a matrix? 
I already thought about taking the inverse, but how do I now on which side I have to multiply the inverse? 

Try writing out the series for $exp$ and simplify the equation before you evaluate!
You wouldn't have to worry about dividing!
