MCQ
Let $f(x)$ be a non-negative continous function such that the area bounded by the curve $y = f(x)$, $x -$ axis and the ordinates $x = \frac{\pi }{4}$, $x = \beta > \frac{\pi }{4}$ is $\left( {\beta \sin \beta + \frac{\pi }{4}\cos \beta + \sqrt 2 \beta } \right)$. Then $f\;\left( {\frac{\pi }{2}} \right)$ is
  • A
    $\left( {1 - \frac{\pi }{4} - \sqrt 2 } \right)$
  • $\left( {1 - \frac{\pi }{4} + \sqrt 2 } \right)$
  • C
    $\left( {\frac{\pi }{4} + \sqrt 2 - 1} \right)$
  • D
    $\left( {\frac{\pi }{4} - \sqrt 2 + 1} \right)$

Answer

Correct option: B.
$\left( {1 - \frac{\pi }{4} + \sqrt 2 } \right)$
b
(b) Given that, $\int_{\pi /4}^\beta {f\;(x)dx} $

$ = \beta \sin \beta + \frac{\pi }{4}\cos \beta + \sqrt 2 \beta $

Differentiating w.r.t. $\beta$, we get

$\therefore $ $f(\beta ) = \sin \beta + \beta \cos \beta - \frac{\pi }{4}\sin \beta + \sqrt 2 $,

Hence, $f\;\left( {\frac{\pi }{2}} \right) = \left( {1 - \frac{\pi }{4} + \sqrt 2 } \right)$.

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

Read the following mathematical statements carefully :

$I.$ Adifferentiable function $' f '$ with maximum at $x = c$ ==> $ f "(c) < 0$.

$II.$ Antiderivative of a periodic function is also a periodic function.

$III.$ If $f$ has a period $T$ then for any $a \in R$. $\int\limits_0^T {f(x)\,dx} = \int\limits_0^T {f(x + a)\,dx} $

$IV.$ If $f (x)$ has a maxima at $x = c$ , then $'f '$ is increasing in $(c - h, c)$ and decreasing in $(c, c + h)$ as $h \rightarrow 0$ for $h > 0.$ Now indicate the correct alternative.

If the function $f(x) = \,\left\{ {\begin{array}{*{20}{c}}{5x - 4}&,&{{\rm{if}}}&{0 < x \le 1}\\{4{x^2} + 3bx}&,&{{\rm{if}}}&{1 < x < 2}\end{array}} \right.$ is continuous at every point of its domain, then the value of $b$ is
If the matrix $\mathrm{A}$ is both symmetric and skew symmetric, then
The solution of $y' - y = 1,\;y(0) = - 1$ is given by $y(x) = $
For $f(x)\, = \,{x^4}\, + \,\left| x \right|,$ let ${I_1}\, = \,\int\limits_0^\pi  {f(\cos \,x)\,dx}$ and ${I_2}\, = \,\int\limits_0^{\frac{\pi }{2}} {f({\mathop{\rm Sin}\nolimits} \,x)\,dx}$ then $\frac{{{I_1}}}{{{I_2}}}$ is equal to
The locus of the centre of a circle which touches externally the circle ${x^2} + {y^2} - 6x - 6y + 14 = 0$ and also touches the $y$-axis, is given by the equation
If the point $(x, -1)$, $(3, y)$, $(-2,3)$ and $(-3, -2)$ be the vertices of a parallelogram, then
If $y = f(x) = ax^2 + 2bx + c = 0$ has Imaginary roots and $4a + 4b + c < 0$ then :-
If $\mathrm{A}=\{\mathrm{x} \in {R}:|\mathrm{x}-2|>1\}, \mathrm{B}=\left\{\mathrm{x} \in {R}: \sqrt{\mathrm{x}^{2}-3}>1\right\}$, $\mathrm{C}=\{\mathrm{x} \in {R}:|\mathrm{x}-4| \geq 2\}$ and ${Z}$ is the set of all integers, then the number of subsets of the set $(A \cap B \cap C)^{c} \cap {Z}$ is .... .
Let $f: R \rightarrow R$ be a function defined by $f(x)=(2+3 a) x^{2}+\left(\frac{a+2}{a-1}\right) x+b, a \neq 1$. If $f(x+y)=f(x)+f(y)+1-\frac{2}{7} x y$, then the value of $28 \sum_{i=1}^{5}|f(i)|$ is: