Thread: Having problems finding a value for X using derivatives.

read what i said

Originally Posted by Petrus

when u find a max and min point u derivate and set to zero then u put it on second derivate and se if its possitive i think its a min point and if its negative its max. wait for some1 to confirme im kinda tired so i can write wrong <.<

Yes, to find potential extrema, you equate the first derivative to zero and solve for x to get the critical number(s).

Then, evaluate the second derivative at these critical number(s), and if the result is positive you have a relative minimum, if it is negative you have a relative maximum, and if it is zero then there is no extremum at that point.

Originally Posted by MarkFL2

Yes, to find potential extrema, you equate the first derivative to zero and solve for x to get the critical number(s).

Then, evaluate the second derivative at these critical number(s), and if the result is positive you have a relative minimum, if it is negative you have a relative maximum, and if it is zero then there is no extremum at that point.

And to evaluate the minimum VALUE, substitute this critical number back into the original equation.