Proof: Integral is finite (Fubini/Tonelli?)

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ChemEng1
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Homework Statement


Let f:[0,1]→ℝ be non-negative and integrable. Prove that [itex]\int_{[0,1]}\frac{f(y)}{|x-y|^{1/2}}dy[/itex] is finite for ae x in [0,1]

Homework Equations


This looks like a Fubini/Tonelli's Theorem problem from the problem givens.

The Attempt at a Solution


I honestly don't know where to start with this problem. Any help or gentle nudges would be appreciated.
 
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Here's what I am thinking.

Consider: [itex]\int_{[0,1]}f(y)\left[\int_{[0,1]}\frac{1}{|x-y|^{1/2}}dx\right]dy=\int_{[0,1]}f(y)\left[2\left(\sqrt{1-y}-\sqrt{y}\right)\right]dy\leq\int_{[0,1]}f(y)\cdot 2<∞[/itex]. Therefore [itex]\int_{[0,1]^{2}}\frac{f(y)}{|x-y|^{1/2}}<\infty[/itex] by Tonelli's Theorem. Then [itex]\int_{[0,1]}\frac{f(y)}{|x-y|^{1/2}}dy[/itex] is finite for ae x in [0,1] again by Tonelli.

Think I still need to add some measurability and non-negative qualifiers, but this is close.

Thoughts?
 
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