# An integral inequality

## Homework Statement

suppose f(x) is monotonely decreasing and positive on [2,+∞),
here "∫ "means integrating on the interval [2,x]

none

## The Attempt at a Solution

Maybe the second mean value thereom of integral is helpful.

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HallsofIvy
Have you tried anything? In particular, have you selected some simple monotonically decreasing function, such as $f(x)= \frac{1}{x}$ and calculated those two values?