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daniel_i_l
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Homework Statement
if f is monotonic and continues in R, and [tex]\int^{\infty}_{a} f(x)dx[/tex] converges then
[tex]lim_{x \rightarrow \infty} xf(x) = 0 [/tex]
Homework Equations
The Attempt at a Solution
I know that if xf(x) converges at all then it has to convergs to 0. But how do I know that it converges?
Thanks.