MCQ
$\int_{}^{} {\frac{{dx}}{{1 + 3{{\sin }^2}x}} = } $
  • A
    $\frac{1}{3}{\tan ^{ - 1}}(3{\tan ^2}x) + c$
  • $\frac{1}{2}{\tan ^{ - 1}}(2\tan x) + c$
  • C
    ${\tan ^{ - 1}}(\tan x) + c$
  • D
    None of these

Answer

Correct option: B.
$\frac{1}{2}{\tan ^{ - 1}}(2\tan x) + c$
b
(b)$\int_{}^{} {\frac{{dx}}{{1 + 3{{\sin }^2}x}}} = \int_{}^{} {\frac{{dx}}{{{{\sin }^2}x + {{\cos }^2}x + 3{{\sin }^2}x}}} $
$ = \int_{}^{} {\frac{{dx}}{{4{{\sin }^2}x + {{\cos }^2}x}}} = \int_{}^{} {\frac{{{{\sec }^2}x\,dx}}{{4{{\tan }^2}x + 1}} = \frac{1}{4}\int_{}^{} {\frac{{{{\sec }^2}x\,dx}}{{{{\tan }^2}x + \frac{1}{4}}}} } $
Put $t = \tan x \Rightarrow dt = {\sec ^2}x\,dx,$ then it reduces to
$\frac{1}{4}\int_{}^{} {\frac{{dt}}{{{t^2} + {{\left( {\frac{1}{2}} \right)}^2}}}} = \frac{1}{4}2{\tan ^{ - 1}}(2t) + c$
$ = \frac{1}{2}{\tan ^{ - 1}}(2t) + c = \frac{1}{2}{\tan ^{ - 1}}(2\tan x) + 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

$\int\frac{\text{x}^3}{\text{x}+1}\text{ dx}$ is equal to:
$\int_{\,0}^{\,\pi } {{e^{{{\sin }^2}x}}{{\cos }^3}x\,dx} $ is equals to
$\int\limits_{ - 3\pi }^{3\pi } {{{\sin }^2}\theta \,{{\sin }^2}\,2\theta d\theta }$ is equal to -
If ${\left\{ {\left( \begin{gathered}
  3\,\,1\,\,2 \hfill \\
  8\,\,9\,\,5 \hfill \\
  1\,\,\,1\,\,3 \hfill \\ 
\end{gathered}  \right)\,\left( \begin{gathered}
  1\,\,3\,\,3 \hfill \\
  3\,\,2\,\,7 \hfill \\
  3\,\,7\,\,9 \hfill \\ 
\end{gathered}  \right)\left( \begin{gathered}
  3\,\,8\,\,1 \hfill \\
  1\,\,\,9\,\,1 \hfill \\
  2\,\,5\,\,3 \hfill \\ 
\end{gathered}  \right)} \right\}^2}\, = \,\left( \begin{gathered}
  a_1\,\,a_2\,\,a_3 \hfill \\
  b_1\,\,b_2\,\,b_3 \hfill \\
  c_1\,\,c_2\,\,c_3 \hfill \\ 
\end{gathered}  \right)$ 

then the value of $|a_2 - b_1| + |a_3 - c_1| + |b_3 - c_2|$ is

Function  $f(x) = \left\{ {\begin{array}{*{20}{c}}   {sgn \left( {\left[ x \right]} \right)\,\,\,\,;\,\,\,x \ne I} \\   {\left[ {sgn \left( x \right)} \right]\,\,\,;\,\,\,x = I} \end{array}} \right.$ is '( where $sgn ()$ denotes signum function $and$ $[.]$ denotes greatest integer function )
Let $A\, = \,\left( {\begin{array}{*{20}{c}}
0&{2q}&r\\
p&q&{ - r}\\
p&{ - q}&r
\end{array}} \right)$. If $A{A^T}\, = \,{I_3},\,\left| p \right|$ then $\left| p \right|$ is
In a $\triangle\text{ABC},$ if C is a right angle, then $\tan^{-1}\Big(\frac{\text{a}}{\text{b}+\text{c}}\Big)+\tan^{-1}\Big(\frac{\text{b}}{\text{c}+\text{b}}\Big)=$
The volume of the parallelopiped whose conterminous edges are $i-j+k,\,\,2i-4j+5k$  and $3i-5j+2k$  is
The population $P = P ( t )$ at time ${ }^{\prime} t ^{\prime}$ of a certain species follows the differential equation $\frac{ dP }{ dt }=0.5 P -450 .$ If $P (0)=850,$ then the time at which population becomes zero is
Choose the correct answer : Smaller area enclosed by the circle $x^2 + y^2 = 4$ and the line $x + y = 2$ is: