SOLUTION: Find the sum of the infinite series (1 + 2 + 3 + 4 + .... + r-1) divided by r! where r is from {{{ 2 to inf }}}?
[Note: Here r! means factorial of r]
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-> SOLUTION: Find the sum of the infinite series (1 + 2 + 3 + 4 + .... + r-1) divided by r! where r is from {{{ 2 to inf }}}?
[Note: Here r! means factorial of r]
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Question 1184396: Find the sum of the infinite series (1 + 2 + 3 + 4 + .... + r-1) divided by r! where r is from ?
[Note: Here r! means factorial of r] Answer by ikleyn(52900) (Show Source):
You can put this solution on YOUR website! .
Find the sum of the infinite series (1 + 2 + 3 + 4 + .... + r-1) divided by r! where r is from
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The sum 1 + 2 + 3 + . . . + (r-1) is .
This sum divided by r! is .
So, the problem asks about this sum .
It is the same as the expression .
The last expression value is , where "e" is the base of natural logarithms.
ANSWER. The requested sum is equal to = = 1.35914 (rounded).
