For ∣x∣<1, we have that
(1+x)^(1/2) =1+(1/2)x+((((1/2))((1/2)−1))/(2!))x^2 +(((1/2)((1/2)−1)((1/2)−2))/(3!))x^3 +...
(1+x)^(1/2) =1+Σ_(r=1) ^∞ ((Π_(k=0) ^(r−1) (0.5−k))/(r!))x^r .
Let g(r)=Π_(k=0) ^(r−1) (0.5−k).
Is it true that for x=(1/2)i⇒∣x∣=0.5<1
(1+(1/2)i)^(1/2) =1+Σ_(r=1) ^∞ ((g(r))/(r!))×(1/2^r )i^r ?
(i=(√(−1)))