MCQ
$\int_{}^{} {\frac{{{e^x}}}{{(1 + {e^x})(2 + {e^x})}}dx = } $
  • A
    $\log [(1 + {e^x})(2 + {e^x})] + c$
  • $\log \left[ {\frac{{1 + {e^x}}}{{2 + {e^x}}}} \right] + c$
  • C
    $\log [(1 + {e^x})\sqrt {2 + {e^x}} ] + c$
  • D
    None of these

Answer

Correct option: B.
$\log \left[ {\frac{{1 + {e^x}}}{{2 + {e^x}}}} \right] + c$
b
(b)$\int_{}^{} {\frac{{{e^x}}}{{(1 + {e^x})(2 + {e^x})}}\,dx} = \int_{}^{} {\left\{ {\frac{{{e^x}}}{{1 + {e^x}}} - \frac{{{e^x}}}{{2 + {e^x}}}} \right\}dx} $
Now put $1 + {e^x} = t$ and $2 + {e^x} = t,$ then the required integral $ = \log (1 + {e^x}) - \log (2 + {e^x}) = \log \left( {\frac{{1 + {e^x}}}{{2 + {e^x}}}} \right) + c.$

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

Let $X=\{11,12,13, \ldots ., 40,41\}$ and $Y=\{61,62$, $63, \ldots ., 90,91\}$ be the two sets of observations. If $\bar{x}$ and $\bar{y}$ are their respective means and $\sigma^2$ is the variance of all the observations in $X \cup Y$, then $\left|\overline{ x }+\overline{ y }-\sigma^2\right|$ is equal to $.................$.
The sum of the series $1 + 2 \times 3 + 3 \times 5 + 4 \times 7 + .......$ upto $11^{th}$ term is
Let $x=-1$ and $x=2$ be the critical points of the function $\mathrm{f}(\mathrm{x})=\mathrm{x}^{3}+\mathrm{ax}^{2}+\mathrm{b} \log _{\mathrm{e}}|\mathrm{x}|+1, \mathrm{x} \neq 0$. Let $m$ and M respectively be the absolute minimum and the absolute maximum values of f in the interval $\left[-2,-\frac{1}{2}\right]$. Then $|\mathrm{M}+m|$ is equal to
(Take $\log _{\mathrm{e}} 2=0.7$ ):
If the given lines $y = {m_1}x + {c_1},y = {m_2}x + {c_2}$ and $y = {m_3}x + {c_3}$ be concurrent, then
The values of $x $ in the following determinant equation, $\left| {\,\begin{array}{*{20}{c}}{a + x}&{a - x}&{a - x}\\{a - x}&{a + x}&{a - x}\\{a - x}&{a - x}&{a + x}\end{array}\,} \right| = 0$ are
If $\sum\limits_{i = 1}^{18} {({x_i} - 8) = 9} $ and $\sum\limits_{i = 1}^{18} {({x_i} - 8)^2 = 45} $ then the standard deviation of $x_1, x_2, ...... x_{18}$ is :-
The sum of the solutions of the equation $\left| {\sqrt x  - 2} \right| + \sqrt x \left( {\sqrt x  - 4} \right) + 2 = 0\left( {x > 0} \right)$ is equal to
$\int_{}^{} {\frac{1}{{(x - 1)({x^2} + 1)}}dx} = $
$A, B, C, D, E $ are five coplanar points, then $\overrightarrow {DA} + \overrightarrow {DB} + \overrightarrow {DC} + \overrightarrow {AE} + \overrightarrow {BE} + \overrightarrow {CE} $ is equal to
Through the vertex $O$ of the parabola, $y^2 = 4ax $ two chords $OP\  \&\ OQ$  are drawn and the circles on $OP\  \&\ OQ$  as diameters intersect in $R.$  If  $\theta _1, \theta _2 \&  \phi $ are the angles made with the axis by the tangents at $P\  \&\  Q$  on the parabola and by $OR$  then the value of, $\cot \theta _1 + \cot \theta _2 $ =