MCQ
$\int\limits_0^{\frac{\pi }{2}} {\,\,\sqrt {\sin \,2\theta } } \sin\, \theta \,d\theta$ is equal to :
  • A
    $0$
  • $\pi /4$
  • C
    $\pi /2$
  • D
    $\pi$

Answer

Correct option: B.
$\pi /4$
b
$I =\int\limits_0^{\frac{\pi }{2}} {\,\,\sqrt {\sin \,2\theta } }$$.\cos\, \theta \,d\theta$ $\Rightarrow 2 \,I = \int\limits_0^{\frac{\pi }{2}} {\,\,\sqrt {\sin \,2\theta } } (\cos\, \theta + \sin\, \theta )\, d\theta$
$= \int\limits_0^{\frac{\pi }{2}} {\,\,\sqrt {1\,\, - \,\,{{\left( {\sin \,\theta \,\, - \,\,\cos \,\theta } \right)}^2}} }  . (\cos\, \theta + \sin \,\theta )\, d\theta$ Put $\sin \,\theta - \cos\, \theta = t$

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

Statement $-1 :$  The point $A(1, 0, 7)$ is the mirror image of the point $B( 1, 6, 3)$ in the line:  $\frac{x}{1} = \frac{{y - 1}}{2} = \frac{{z - 2}}{3}$

Statement $-2 :$ The line $\frac{x}{1} = \frac{{y - 1}}{2} = \frac{{z - 2}}{3}$ bisects the line joining $A(1, 0, 7)$ and $B( 1, 6, 3)$

If $A$ and $B$ are two independent events such that $P\,(A) = \frac{1}{2},\,\,P(B) = \frac{1}{5},$ then
If the roots of the equation $x^3 - 9x^2 + \alpha x - 15 = 0 $ are in $A.P.$, then $\alpha$  is 
A multiple choice examination has $5$ questions. Each question has three alternative answers of which exactly one is correct. The probability that a student will get $4$ or more correct answers just by guessing is :
Let $a_1, a_2, a_3, \ldots$ be in an arithmetic progression of positive terms.

Let $\mathrm{A}_{\mathrm{k}}=\mathrm{a}_1{ }^2-\mathrm{a}_2{ }^2+\mathrm{a}_3{ }^2-\mathrm{a}_4{ }^2+\ldots+\mathrm{a}_{2 \mathrm{k}-1}{ }^2-\mathrm{a}_{2 \mathrm{k}}{ }^2$.

If $\mathrm{A}_3=-153, \mathrm{~A}_5=-435$ and $\mathrm{a}_1{ }^2+\mathrm{a}_2{ }^2+\mathrm{a}_3{ }^2=66$, then $\mathrm{a}_{17}-\mathrm{A}_7$ is equal to....................

A cone of maximum volume is inscribed in a given sphere, then ratio of the height of the cone to diameter of the sphere is
The value of the determinant$\left| {\,\begin{array}{*{20}{c}}1&1&1\\1&{1 - x}&1\\1&1&{1 + y}\end{array}\,} \right|$is
$\alpha ,\beta ,\gamma $ are roots of $x^3 + x^2 - 5x - 1 = 0$ , then value of $[\alpha ]+[\beta ]+[\gamma ]$ is $($where $[.]$ denotes greatest integer function)
If the midpoint of a chord of the ellipse $\frac{x^2}{9}+\frac{y^2}{4}=1$ is $(\sqrt{2}, 4 / 3)$, and the length of the chord is $\frac{2 \sqrt{\alpha}}{3}$, then $\alpha$ is :
If $A \ne O$ and $B \ne O$ are $ n × n$ matrix such that $AB = O,$ then