MCQ
The value of $\int_{ - a}^a {\frac{1}{{x + {x^3}}}dx} $ is
  • $0$
  • B
    $\int_0^a {\frac{1}{{1 + {x^6}}}\;} dx$
  • C
    $2\int_0^a {\frac{1}{{1 + {x^3}}}\;} dx$
  • D
    $\int_0^a {\frac{1}{{1 + {{(a - x)}^3}}}\;} dx$

Answer

Correct option: A.
$0$
a
(a) Since $\int_{ - a}^a {f(x)} \;dx = 0$, 

if $f( - x) = - f(x)$

Therefore, $\int_{ - a}^a {\frac{{dx}}{{x + {x^3}}}} = 0$.

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

The mean and variance of $20$ observations are found to be $10$ and $4,$ respectively. On rechecking, it was found that an observation $9$ was incorrect and the correct observation was $11$. Then the correct variance is
Let $g$ be a differentiable function such that $\int_0^x g(t) d t=x-\int_0^x \operatorname{tg}(t) d t, x \geq 0$ and let $y=y(x)$ satisfy the differential equation $\frac{d y}{d x}-y \tan x=$ $2(x+1) \sec x g(x), x \in\left[0, \frac{\pi}{2}\right)$. If $y(0)=0$, then $y \left(\frac{\pi}{3}\right)$ is equal to
Let $f: R \rightarrow R$ be defined as

$f(x)=\left\{\begin{array}{ccc}x^{5} \sin \left(\frac{1}{x}\right)+5 x^{2}& , & x<0 \\ 0 & , & x=0 \\ x^{5} \cos \left(\frac{1}{x}\right)+\lambda x^{2} & , & x>0\end{array} .\right.$

The value of $\lambda$ for which $f^{\prime \prime}(0)$ exists, is

Let $A$ be $2$$ \times $$2$ matrix

Statement $-1 :$  $adj\left( {adj\;A} \right) = A$

Statement $-2 :$ $\left| {adj\;A} \right| = \left| A \right|$

The function $f(x) = x\, + \,\cos x$ is
Let $\ce{ABCD}$ and $\ce{AEFG}$ be squares of side $4$ and $2$ units, respectively. The point $E$ is on the line segment $AB$ and the point $F$ is on the diagonal $AC.$ Then the radius $r$ of the circle passing through the point $F$ and touching the line segments $BC$ and $CD$ satisfies :
${x^x}$ has a stationary point at
If the line $lx + my + n = 0$ is a tangent to the parabola ${y^2} = 4ax$, then locus of its point of contact is
${\cot ^{ - 1}}( - \sqrt 3 ) =$
The axis of the parabola $9{y^2} - 16x - 12y - 57 = 0$ is