推 Eliphalet :a_n = (1/n) * (na_n) 01/02 17:50
→ bineapple :反證嗎? 我想過設Σna_n收斂 然後分絕對和條件去證 01/02 20:27
→ bineapple :可是條件收斂的case好像沒那麼好講.... 01/02 20:27
推 newversion :lim a_n/(na_n)=0 ==> Σna_n控制Σa_n 01/02 21:51
→ bineapple :感謝樓上兩位大大~ 01/02 22:19