MCQ
$\int {\frac{{{x^2}}}{{{x^2} + 4}}\,\,dx} $ equals to
  • $x - 2{\tan ^{ - 1}}(x/2) + c$
  • B
    $x + 2{\tan ^{ - 1}}(x/2) + c$
  • C
    $x - 4{\tan ^{ - 1}}(x/2) + c$
  • D
    $x + 4{\tan ^{ - 1}}(x/2) + c$

Answer

Correct option: A.
$x - 2{\tan ^{ - 1}}(x/2) + c$
a
(a) $I = \int {\frac{{{x^2}}}{{{x^2} + 4}}dx} $$ = \int {\frac{{{x^2} + 4 - 4}}{{({x^2} + 4)}}dx} $
==> $I = \int {\left[ {1 - \frac{4}{{{x^2} + 4}}} \right]\,dx} $$ = \int {dx - \int {\frac{4}{{{x^2} + 4}}dx} } $
$ \Rightarrow I = x - 4\int {\frac{{dx}}{{{x^2} + {{(2)}^2}}}} $$ = x - \frac{4}{2}{\tan ^{ - 1}}(x/2) + c$
$ = x - 2{\tan ^{ - 1}}\frac{x}{2} + 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