Ratio Test
THIS TEST IS GOOD FOR FACTORIALS
.
▼Refer to xaktly: Ratio test / root test
Example
Apply the
ratio test
:L = 0
, so the series absolutely converges.
Example
Apply the
ratio test
, leta_(n+1) / a_n
.The trick is to know:
(n+1)! = (n+1)·n!
, and(n+8)! = (n+8)·(n+7)!
Take the limit to get:
According to the ratio test, if
L = 1
, then there's no conclusion.
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