f is a positive decreasing function of x, f(n) = a(adsbygoogle = window.adsbygoogle || []).push({}); _{n}for all n:

[itex]\int\stackrel{n+1}{1} f(x) dx[/itex] [itex]\leq[/itex] a[itex]_{1}[/itex] + a[itex]_{2}[/itex] + [itex]\cdots[/itex] + a[itex]_{n}[/itex]

Why is this true? I think I'm missing a fundamental understanding of summation, since the reasoning for this step was left out in my book.

[edited out some nonsense]

Thanks for any help!

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# Need help with a simple integral proof

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