Question 396581
Is this {{{(4 - sqrt(-8))/2}}} ?
If so, it equals 
{{{(4 - 2*sqrt(-2))/2}}}
{{{2 - sqrt(-2)}}}
{{{2 - sqrt(2)*sqrt(-1)}}}
{{{2 - sqrt(2)*i}}}
{{{a = 2}}}
{{{b = sqrt(2)}}}