relative max and min of 2nd derivative: f(x) = 7x^2 + 5x - 1

[yanarains]

f(x) = -7x^2 + 5x - 1
f'(x) = -14x + 5
f''(x) = -14
Therefore this function is inconclusive. Is this right?
Thanks

 

[stapel]

f(x) = -7x^2 + 5x - 1
f'(x) = -14x + 5
f''(x) = -14
Therefore this function is inconclusive.

What do you mean by the function being "inconclusive"? Do you perhaps mean to ask whether the Second Derivative Test is inconclusive with respect to... whatever the (unstated) instructions asked of you...?

Please be complete. Thank you!

Eliz.

 

[Deleted member 4993]

Re: relative max and min of 2nd derivative: f(x) = 7x^2 + 5x

f(x) = -7x^2 + 5x - 1
f'(x) = -14x + 5
f''(x) = -14
Therefore this function is inconclusive. Is this right?
Thanks

If your original question asked you to find relative maxima or minima (or just proof of existence of relative maxima or minima) - then - you are wrong.

You can definitely prove whether the given function has rel. max/min - conclusively.

You can also graph the function and see for yourself that such point exists.