b) If the convergence of {(∞Σ n=1)an} can be established by ratio test. Is it true that {(∞Σn=1)√(an)} will always converge？Give reason to justify your assertion. (10 marks)
更新1:
sorry，網友提醒，原來b打錯了，應是n√(an)，如下： b) If the convergence of {(∞Σ n=1)an} can be established by ratio test. Is it true that {(∞Σn=1)n√(an)} will always converge？Give reason to justify your assertion. (10 marks)
