2nd Derivative Test Vs Testing Intervals
- Thread starter Jason76
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What "cases" does your book give you? "The answer" is probably related to whatever the author gave you, and you're being asked to repeat that back.In which cases do we use the 2nd derivative test? Can we always use it to find out whether valley shaped curves are min or max?
HallsofIvy
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Obviously not if the second derivtive is 0. Don't forget the first derivative test. Or just common sense.In which cases do we use the 2nd derivative test? Can we always use it to find out whether valley shaped curves are min or max?
In which cases do we use the 2nd derivative test? Can we always use it to find out whether valley shaped curves are min or max?
You also may not wanna do the 2nd derivative test if finding the 2nd derivative is a beast of a challenge.
No, finding the 2nd derivative is easy, as well as testing the 2nd derivative.
I suppose better to just play it safe, and always test intervals.
You obviously have not had to find the 2nd derivative of functions that can become hairy. For example:
\(\displaystyle y = xe^{sec(3x^2+\sqrt{x^2+3x})}\)
And yes, this was on an exam of a kid I tutored, but thankfully he only had to find the first derivative.