Q: Does Σ1/2ⁿ converge? What about Σ1/n (harmonic)? Σ1/2ⁿ: geometric r = 1/2: converges to 1/(1-1/2)... starting 1/2: sum = 1! Σ1/n: harmonic - DIVERGES (group: 1/3+1/4 > 1/2, 1/5+...+1/8 > 1/2...!). Terms → 0 is NECESSARY but not sufficient!