The analytic function f(z)=z−1z2+1 has singularities at
Conisder the complex valued funciton f(z)=2z3+b|z|3 where z is a complex variable. The value of b for which the function f(z) is analytic is
If f(z)=7−z1−z2,wehre z=1+2i,then |f(z)| is