(-11-60i)1/2 =a+ib
(squaring both sides)
-11-60i=(a+ib)2
-11-60i= a2-b2+2iab
(Comparing LHS and RHS)
-11=a2-b2 --------(i)
-60=2iab---------(ii)
{Using identity (a2 +b2)2= (a2-b2)2+(2ab)2}
therefore a2 +b2 = 61-----------(iii)
from eqn (i) and (iii)
a2 +b2 = 61
a2-b2 = -11
------------------------
2a2=50
therfore a=+5
and from eqn (ii)
b= +5
therfore the required eqn is
+(5+i6)
