Find the maximum and minimum values of the function f(x)=4 x+2 +x - Vidyadip

Question

Find the maximum and minimum values of the function $\text{f}(\text{x})=\frac{4}{\text{x}+2}+\text{x}$

✓

Answer

Given, $\text{f}(\text{x})=\frac{4}{\text{x}+2}+\text{x}$
$\Rightarrow\text{f}'(\text{x})=-\frac{4}{(\text{x}+2)^{2}}+1$
For a local maxima or a local minima, We must have f'(x) = 0
$\Rightarrow-\frac{4}{(\text{x}+2)^{2}}+1=0$
$\Rightarrow-\frac{4}{(\text{x}+2)^{2}}=-1$
$(\text{x}+2)^{2}=\pm2$
$\Rightarrow \text{x}=0 \ \text{and} -4$
Thus, x = 0 and x = -4 are the possible of local maxima or local minima.
Now, $\text{f}'(\text{x})=\frac{8}{(\text{x}+2)^{3}}$
At x = 0
$\text{f}''(0)=\frac{8}{(2)^{3}}=1>0$
So, x = 0 is a point of local minimum.
The local minimum value is given by
$\text{f}(0)=\frac{4}{(0+2)}+0=2$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "5 Marks Questions" from Maxima and Minima→Maxima and Minima — all question types→Maths STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Show that the lines $\frac{\text{x}-1}{2}=\frac{\text{y}-1}{3}=\frac{\text{z}-1}{4}$ and $\frac{\text{x}-4}{5}=\frac{\text{y}-1}{2}=\text{z}$ intersect. Also, find their point of intersection.

Find the maximum and minimum value of 2x + y subject to the constraints:

$\text{x}+3\text{y}\geq6,\text{x}-3\text{y}\leq3,3\text{x}+4\text{y}\leq24,$ $-3\text{x}+2\text{y}\leq6,5\text{x}+\text{y}\geq5,\text{x},\text{y}\geq0$

If $\text{A}=\frac{1}{9}\begin{bmatrix}-8 & 1 & 4\\4 & 4 & 7 \\ 1 & -8 & 4 \end{bmatrix},$ prove that $A^{-1} = A^3.$

Find the equation of the line passing through the points $(-1, 2, 1)$ and parallel to the line $\frac{2\text{x}-1}{4}=\frac{3\text{y}+5}{4}=\frac{2-\text{z}}{3}.$

In the following, find the value of the constant k so that the given function is continuous at the indicated point:
$\text{f(x)}=\begin{cases}\frac{\text{x}^2+\text{x}^2-16\text{x}+20}{(\text{x}-2)^2},&\text{ x}\neq2\\\text{k},&\text{x}=2\end{cases}$

Find the points of local maxima or local minima and corresponding local maximum and local minimum values of the following functions. Also, find the points of inflection,
$\text{f}(\text{x})=\text{x}\sqrt{32-\text{x}^{2}}, -5\leq\text{x}\leq5$

Show that the relation R in the set A of points in a plane given by R = {(P, Q) : distance of the point P from the origin is same as the distance of the point Q from the origin}, is an equivalence relation. Further, show that the set of all points related to a point P ≠ (0, 0) is the circle passing through P with origin as centre.

Using elementary transformation, find the inverse of each of the matrices, $\begin{bmatrix}2& 0&-1 \\5 & 1&0\\0&1&3 \end{bmatrix}$

Find the maximum and the minimum values, if any, without using derivaives of the following functions:f(x) = |sin4x + 3| on R.

Evaluate the following intregals:
$\int\frac{\text{x}^2+1}{(2\text{x}+1)(\text{x}^2-1)}\text{ dx}$