Given number: −8nn It is a series of species an(cx−x0)dn - power series. The radius of convergence of a power series can be calculated by the formula: Rd=cx0+limn→∞an+1an In this case an=−n and x0=−8 , d=1 , c=0 then R=∞~(−8+n→∞lim(n+1n)) Let's take the limit we find