已知正項(xiàng)級(jí)數(shù)收斂,試證下列級(jí)數(shù)皆收斂:.
已知正項(xiàng)級(jí)數(shù)un收斂,試證下列級(jí)數(shù)皆收斂:√unun+1.
已知正項(xiàng)級(jí)數(shù)un收斂,試證下列級(jí)數(shù)皆收斂:unun+1.