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主要内容

比值审敛法

问题

a, start subscript, n, end subscript, equals, start fraction, n, minus, 2, divided by, left parenthesis, n, plus, 1, right parenthesis, !, end fraction
1) 算出 limit, start subscript, n, \to, infinity, end subscript, open vertical bar, start fraction, a, start subscript, n, plus, 1, end subscript, divided by, a, start subscript, n, end subscript, end fraction, close vertical bar
limit, start subscript, n, \to, infinity, end subscript, open vertical bar, start fraction, a, start subscript, n, plus, 1, end subscript, divided by, a, start subscript, n, end subscript, end fraction, close vertical bar, equals
  • 你的答案是
  • 一个整数,例如 6
  • 一个精确的十进位小数,例如0, point, 75
  • 一个最简真分数,如 3, slash, 5
  • 一个最简假分数,如 7, slash, 4
  • 一个混合带分数,例如 1, space, 3, slash, 4
2) 根据你的答案,通过比率检验法检验后,S, equals, sum, start subscript, n, equals, 1, end subscript, start superscript, infinity, end superscript, a, start subscript, n, end subscript是什么?
选出正确答案:
不会做了?
不会做了?