For the geometric series ∑n=0∞rn\sum_{n=0}^{\infty} r^n∑n=0∞rn, for what range of rrr does it converge?
∣r∣<1|r| < 1∣r∣<1
∣r∣≤1|r| \leq 1∣r∣≤1
r<1r < 1r<1
∣r∣>1|r| > 1∣r∣>1