If f '(x) changes its sign from positive to negative

Question:

If $f^{\prime}(x)$ changes its sign from positive to negative as $x$ increases through $c$ in the interval $(c-h, c+h)$, then $x=c$ is a point of____________

Solution:

First derivative test states that if '(x) changes sign from positive to negative as x increases through c, then c is a point of local maxima, and f(c) is local maximum value.

Thus, if $f^{\prime}(x)$ changes its sign from positive to negative as $x$ increases through $c$ in the interval $(c-h, c+h)$, then $x=c$ is a point of local maximum.

If $f^{\prime}(x)$ changes its sign from positive to negative as $x$ increases through $c$ in the interval $(c-h, c+h)$, then $x=c$ is a point of __local maximum___.

Leave a comment

Close

Click here to get exam-ready with eSaral

For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.

Download Now