Given number: (x−6)2 It is a series of species ax(cx−x0)dx - power series. The radius of convergence of a power series can be calculated by the formula: Rd=cx0+limx→∞ax+1ax In this case ax=(x−6)2 and x0=0 , d=0 , c=1 then 1=x→∞lim((x−6)2(x−5)21) Let's take the limit we find