Hey I was doing a standard derivative problem but I ran into something somewhat strange. Check it out:(adsbygoogle = window.adsbygoogle || []).push({});

[tex]\frac{d}{dx}\sum_{i=1}^xx=\frac{d}{dx}x^2=2x[/tex]

Okay, simple enough..but what if I write it like this?

[tex]\frac{d}{dx}\sum_{i=1}^xx=\frac{d}{dx}(x+x+...+x)=1+1+...+1=x[/tex].

Why am I getting two different answers???

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# Homework Help: Derivating a sum weird result. wtf

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