(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

yet is approaching negative infiniti?

We were discussing a quesiton that went "suppose f double prime (x)>0 and x ranges from negative infiniti to infiniti, and f(a)=0. Prove or disprove that f(x) is bounded below."

The man said that e^-x - x had a second derivative greater than zero, which i understand, but then how does it go to negative infiniti? I don't understand that, it should go to positive infiniti, right?

2. Relevant equations

3. The attempt at a solution

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# Homework Help: How can there be a function with a second derivative greater than zero

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