MCQ
$\int_0^{\pi /4} {\frac{{{{\sec }^2}x}}{{(1 + \tan x)(2 + \tan x)}}} \,dx = $
  • A
    ${\log _e}\left( {\frac{2}{3}} \right)$
  • B
    ${\log _e}3$
  • C
    $\frac{1}{2}{\log _e}\left( {\frac{4}{3}} \right)$
  • ${\log _e}\left( {\frac{4}{3}} \right)$

Answer

Correct option: D.
${\log _e}\left( {\frac{4}{3}} \right)$
d
(d) Put $1 + \tan x = t \Rightarrow {\sec ^2}x\,dx = dt$

$\therefore \,\,\,\int_0^{\pi /4} {\frac{{{{\sec }^2}x}}{{(1 + \tan x)(2 + \tan x)}}dx} $

$ = \int_1^2 {\frac{{dt}}{{t(1 + t)}}} = \int_1^2 {\frac{{dt}}{t} - \int_1^2 {\frac{{dt}}{{1 + t}}} } = [\log t - \log (1 + t)]_1^2$

$ = {\log _e}2 - {\log _e}3 + {\log _e}2 = {\log _e}\frac{4}{3}$.

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

The function $f(x) = 2{x^3} - 3{x^2} - 12x + 4$ has
Let the radius and height of right circular cylinder is related as $r^2 + h = 6$ .  If the volume of the cylinder is maximum, then $\frac {r}{h}$ is
If ${A_\lambda } = \left( {\begin{array}{*{20}{c}}
\lambda &{\lambda  - 1}\\
{\lambda  - 1}&\lambda 
\end{array}} \right);\,\lambda  \in N$ then $|A_1| + |A_2| + ..... + |A_{300}|$ is equal to
If $0 < x < \frac{1}{\sqrt{2}}$ and $\frac{\sin ^{-1} x}{\alpha}=\frac{\cos ^{-1} x}{\beta}$, then a value of $\sin \left(\frac{2 \pi \alpha}{\alpha+\beta}\right)$ is$......$
$\int_{}^{} {x{{\sin }^2}x\;dx = } $
If $g$ $(x)$ is the inverse of $f$ $(x) $ and $f$ $(x)$ has domain $x \in  [1, 5], $ where $f (1) = 2$ and $f(5) = 10$ then the values of $\int\limits_1^5 {f(x)} dx$ $+\int\limits_2^{10} {g(y)} dy$ equals
If $A = \left[ {\begin{array}{*{20}{c}}1&2&2\\2&1&{ - 2}\\a&2&b\end{array}} \right]$ is a matrix satisfying the equation $AA^T=9I $ where$ I$ is $3×3$ identity matrix, then the ordered pair $(a, b)$ is equal to:
Let a, b, c be positive real numbers. The following system of equations in x, y and z $\frac{\text{x}^2}{\text{a}^2}+\frac{\text{y}^2}{\text{b}^2}-\frac{\text{z}^2}{\text{c}^2}=1,$ $\frac{\text{x}^2}{\text{a}^2}-\frac{\text{y}^2}{\text{b}^2}+\frac{\text{z}^2}{\text{c}^2}=1,$ $-\frac{\text{x}^2}{\text{a}^2}+\frac{\text{y}^2}{\text{b}^2}+\frac{\text{z}^2}{\text{c}^2}=1$ has:
  1. No solution.
  2. Unique solution.
  3. Infinitely many solutions.
  4. Finitely many solutions.
The solution set of the inequation 2x + y > 5 is:
  1. half plane that contains the origin
  2. open half plane not containing the origin
  3. whole xy-plane except the points lying on the line 2x + y = 5
  4. none of these
If $x \phi(x)=\int_{5}^{x}\left(3 t^{2}-2 \phi^{\prime}(t)\right) d t, x\,>\,-2$, and $\phi(0)=4$ then $\phi(2)$ is .... .