MCQ
The integral $\int_{-1}^{\frac{3}{2}}\left(\left|\pi^{2} x \sin (\pi x)\right|\right) d x$ is equal to :
  • A
    $3+2 \pi$
  • B
    $4+\pi$
  • $1+3 \pi$
  • D
    $2+3 \pi$

Answer

Correct option: C.
$1+3 \pi$
(C) $1+3 \pi$
Let, $\mathrm{I}=\pi^{2} \int_{-1}^{3 / 2}|\mathrm{x} \sin \pi \mathrm{x}| \mathrm{dx}$
$=\pi^2\left\{\int_{-1}^1 x \sin \pi xdx -\int_1^{3 / 2} x \sin \pi xdx \right\}$
$=\pi^2\left\{2 \int_0^1 x \sin \pi xdx -\int_{-1}^{3 / 2} x \sin \pi xdx \right\}$
Consider
$\int x \sin \pi x d x$
$-\mathrm{x} \cdot \frac{1}{\pi} \cos \pi \mathrm{x}+\int 1 \cdot \frac{1}{\pi} \cos \pi \mathrm{xdx}$
$=-\frac{\mathrm{x}}{\pi} \cos \pi \mathrm{x}+\frac{\sin \pi \mathrm{x}}{\pi^{2}}$
$\mathrm{I}=\pi^{2}\left\{2\left(-\frac{\mathrm{x}}{\pi} \cos \pi \mathrm{x}+\frac{\sin \pi \mathrm{x}}{\pi^{2}}\right)_{0}^{1}-\left(-\frac{\mathrm{x}}{\pi} \cos \pi \mathrm{x}+\frac{\sin \pi \mathrm{x}}{\pi^{2}}\right)_{1}^{3 / 2}\right\}$
$=\pi^{2}\left\{\frac{2}{\pi}-\left(-\frac{1}{\pi^{2}}-\frac{1}{\pi}\right)\right\}$
$=\pi^{2}\left\{\frac{3}{\pi}+\frac{1}{\pi^{2}}\right\}$
$=3 \pi+1$

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 $z = \sec \,(y - ax) + \tan (y + ax),$ then ${{{\partial ^2}z} \over {\partial {x^2}}} - {a^2}{{{\partial ^2}z} \over {\partial {y^2}}} = $
If two vertices of a triangle are $(5, -1)$ and $( - 2, 3)$ and its orthocentre is at $(0, 0)$, then the third vertex
The sum of first four terms of a geometric progression $(G.P.)$ is $\frac{65}{12}$ and the sum of their respective reciprocals is $\frac{65}{18} .$ If the product of first three terms of the $G.P.$ is $1,$ and the third term is $\alpha$, then $2 \alpha$ is ....... .
Inverse of the matrix $\left[ {\begin{array}{*{20}{c}}{\cos 2\theta }&{ - \sin 2\theta }\\{\sin 2\theta }&{\cos 2\theta }\end{array}} \right]$ is
Let $O$ be the origin and $\overline{ OA }=2 \hat{ i }+2 \hat{ j }+\hat{ k }, \overline{ OB }=\hat{ i }-2 \hat{ j }+2 \hat{ k }$ and $\overline{ OC }=\frac{1}{2}(\overline{ OB }-\lambda \overline{ OA })$ for some $\lambda>0$. If $|\overline{ OB } \times \overline{ OC }|=\frac{9}{2}$, then which of the following statements is (are) TRUE?

$(A)$ Projection of $\overline{ OC }$ on $\overline{ OA }$ is $-\frac{3}{2}$

$(B)$ Area of the triangle $OAB$ is $\frac{9}{2}$

$(C)$ Area of the triangle $ABC$ is $\frac{9}{2}$

$(D)$ The acute angle between the diagonals of the parallelogram with adjacent sides $\overline{ OA }$ and $\overline{ OC }$ is $\frac{\pi}{3}$

$\int_{}^{} {{x^{51}}({{\tan }^{ - 1}}x + {{\cot }^{ - 1}}x)\;dx = } $
If $f(x)$ be such that $f(x) = max (|2-x|, 2-x^3), x \in R$
If the co-ordinates of the points $A,B,C,D$ be $(2, 3, -1), (3, 5, -3), (1, 2, 3)$ and $(3, 5, 7)$ respectively, then the projection of $AB$ on $CD$ is
The position vector of coplanar points $A, B, C, D$ are $a, b, c$ and $d$ respectively, in such a way that $(a - d)\,.\,(b - c) = (b - d)\,.\,(c - a) = 0,$ then the point $D$ of the triangle $ABC$ is
The equation of common tangents to the parabola ${y^2} = 8x$ and hyperbola $3{x^2} - {y^2} = 3$, is