MCQ
The value of $\int_{\,0}^{\,1} {\,\frac{{dx}}{{x + \sqrt {1 - {x^2}} }}} $ is
  • A
    $\frac{\pi }{3}$
  • B
    $\frac{\pi }{2}$
  • C
    $\frac{1}{2}$
  • $\frac{\pi }{4}$

Answer

Correct option: D.
$\frac{\pi }{4}$
d
(d) $\int_0^1 {\frac{{dx}}{{x + \sqrt {1 - {x^2}} }} = \int_0^{\pi /2} {\frac{{\cos \theta \,d\theta }}{{\sin \theta + \cos \theta }}} } $

$ = \frac{\pi }{4}$,

(Put $x = \sin \theta ,\,dx = \cos \theta \,d\theta $).

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

If $\text{f}(\text{x})=\text{e}^{\cos^{-1}\big\{\sin\big(\text{x}+\frac{\pi}{3}\big)\big\}}$ then $\text{f}\Big(\frac{8\pi}{9}\Big)=$
  1. $\text{e}^{\frac{5\pi}{18}}$
  2. $\text{e}^{\frac{13\pi}{18}}$
  3. $\text{e}^{\frac{-2\pi}{18}}$
  4. $\text{none of these}$
If the determinant $\begin{vmatrix}\text{a}&\text{b}&2\text{a}\alpha+3\text{b}\\\text{b}&\text{c}&2\text{b}\alpha+3\text{c}\\2\text{a}\alpha+ 3\text{b}&2\text{b}\alpha+3\text{c}&0\end{vmatrix}=0,$ then:
  1. a, b, c are in H.P.
  2. $\alpha$ is a root of 4ax2 + 12bx + 9c = 0 or a, b, c are in G.P.
  3. a, b, c are in G.P. only.
  4. a, b, c are in A.P.
If $f(x) = \left\{ {\begin{array}{*{20}{c}}  {\frac{{\sin x}}{x} + \cos x,} \, & \,when \,\, {x \ne 0} \\   {2,} \,& \,\,when\,\,{x = 0} \end{array}} \right.$  then 
Let $\text{A}=\{\text{x}:-1\leq\text{x}\leq1\}$ and f : A → A such that $\text{f(x)}=\text{x}|\text{x}|,$ then f is:
  1. A bijection.
  2. Injective but not surjective.
  3. Surjective but not injective.
  4. Neither injective nor surjective.
Differential coefficient of $\sqrt{\sec \sqrt{x}}$ is
The differential equation of the family of curves ${y^2} = 4a(x + a)$, where $a$ is an arbitrary constant, is
If $\sin \left( {{{\sin }^{ - 1}}\frac{1}{5} + {{\cos }^{ - 1}}x} \right) = 1$, then $x$ is equal to
If $x, y, z$ are nonzero real numbers, then the inverse of matrix $\mathrm{A}=\left[\begin{array}{lll}x & 0 & 0 \\ 0 & y & 0 \\ 0 & 0 & z\end{array}\right]$ is
The number that exceeds its square by the greatest amount is
The rate of change of the area of a circle with respect to its radius $r$ at $r=4 cm$ is