Let S be the interior of the circle |z − 1 − i| = 1. Show, by using suitable inequalities for |z1 ± z2|, that if z ∈ S then √5 − 1 < |z − 3| < √5 + 1.

Obtain the same result geometrically by considering the line containing the centre of the circle and the point 3.

I'm not making headway with this question, so please help, thanks.