Question
Find the interval in which $f(x)=\log (1+x)-\frac{x}{1+x}$ is increasing.

Answer

(a) : Here, $f^{\prime}(x)=\frac{x}{(1+x)^2}$
So, critical point is $x=0$ only.
and disjoint intervals are $(-\infty, 0)$ and $(0, \infty)$.
So, $f(x)$ is increasing in $(0, \infty)$ and decreasing in $(-\infty, 0)$.

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

Similar questions

Choose the correct answer in each of the following:
If A and B are two events such that P(A) ≠ 0 and P(B | A) = 1, then
If the direction cosines of a line are $\left(\frac{1}{a}, \frac{1}{a}, \frac{1}{a}\right)$, then:
If $\vec{\text{a}},\vec{\text{b}},\vec{\text{c}}$ are non-coplanar vectors, then $\frac{\vec{\text{a}}.\big(\vec{\text{b}}\times\vec{\text{c}}\big)}{\big(\vec{\text{c}}\times\vec{\text{a}}\big).\vec{\text{b}}}+\frac{\vec{\text{b}}.\big(\vec{\text{a}}\times\vec{\text{c}}\big)}{\vec{\text{c}}.\big(\vec{\text{a}}\times\vec{\text{b}}\big)}$ is equal to:
  1. 0
  2. 2
  3. 1
  4. None of these
If a line makes angles $Q_1, Q_{21}$ and $Q_3$ respectively with the coordinate axis then the value of $\cos^2 \text{Q}_{1} + \cos^2 \text{Q}_{2} + \cos^2 \text{Q}_{3}$:
Choose the correct answer from the given four options.
Let F = 3x - 4y be the objective function.
Minimum value of F is:
  1. 0.
  2. -16.
  3. 12.
  4. Does not exist.
If $A$ and $B$ are two events such that $P(A \cup B)=\frac{5}{6}, P(A \cap B)=\frac{1}{3}$ and $P(\bar{B})=\frac{1}{2}$ then the events $A$ and $B$ are
A relation R is defined as $R =\{(1,2)\}$ on set $A =$ $\{1,2,3\}$, then R is :
If the vectors $4\hat{\text{i}}+11\hat{\text{j}}+\text{m}\hat{\text{k}},7\hat{\text{i}}+2\hat{\text{j}}+6\hat{\text{k}}$ and $\hat{\text{i}}+5\hat{\text{j}}+4\hat{\text{k}}$ are coplanar, then $m =$
If $x=f(t)$ and $y=g(t)$ are differentiable functions of $t$, then $\frac{d^2 y}{d x^2}$ is
The function f(x) = x − [x], where [⋅] denotes the greatest integer function is:
  1. Continuous everywhere.
  2. Continuous at integer points only.
  3. Continuous at non-integer points only.
  4. Differentiable everywhere.