Question 785008
{{{z^2 = i}}}
{{{z^2 - sqrt(-1) =0}}}

{{{z^2-root(4,-1)^2=0}}}

{{{(z+root(4,-1))(z-root(4,-1))=0}}}

solutions:

{{{z=root(4,-1)}}}

or

{{{z=-root(4,-1)}}}