Question 81579
Yes, but you will get an imaginary number.
{{{(sqrt(-4))}}}
4i
.
  You will not get a real number because there is no real number that can be squared and equal a negative number.  For example: 2^2=4 and so does (-2)^2=4.  Both will equal a positive 4.  So the {{{(sqrt(4))}}}=+2 or -2.