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Homework Statement
[tex]\Sigma[/tex] (from index k = 1 until infinity)
Within the Sigma is the series : (k! * (x^k))
Homework Equations
Ratio Test : lim as k approaches infinity |a(k+1) / ak|
The Attempt at a Solution
When I apply the ration test to the series and simplify I get lim k --> inf (x * (k+1))
My confusion lies in the fact that the text answers this limit as infinity(which is pretty obvious if you're only taking k into consideration) and they pull the x out in front of the limit. I thought you could only do that with constants?