(adsbygoogle = window.adsbygoogle || []).push({}); !!!Really quick qestion about minimum of function

I ADDED ANOTHER QUESTION IN POST #3 ! Thanks for looking :)

I am told the a jet's follows the curve [itex]y=20(10^{-6})x^2+5000[/itex] where yANDx are in feet. Basically all I need help with is for the first part of the problem, I need to find out where the jet is at its LOWEST point on the curve.

I am pretty sure this is at x=0. But how can I prove it? Usually I would just plug in zero for x. But this is not a function of time, it is of position, so I am not quite sure how to show that if I plug in a neg number I would not get a number less than 5000. I mean I know since it's an even function thath even numbers<0 for x will yield numbers>5000.

I was hoping to show this with Calculus rather than analysis, though maybe the latter is more reasonable in an engineering course?

Any thoughts are welcome, I can move on withthe problem regardless (since I could use the analysis) but I just want some input.

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# Homework Help: Really quick question about minimum of function

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