Example

> sqrt(4)
        2
> sqrt(-4)
        0 + 2i
> sqrt(-40-34j)
      2.5 - 6.8i
> c = rand(2,5)*20 
 c =
       20       12.9      0.739       13.3       4.08  
     19.5       6.66       3.23       1.69       3.35  
> sqrt(c)
     4.47        3.6       0.86       3.65       2.02  
     4.41       2.58        1.8        1.3       1.83