MCQ
Let $[t]$ denote the largest integer less than or equal to $t$. If

$\int_0^3\left(\left[x^2\right]+\left[\frac{x^2}{2}\right]\right) d x=a+b \sqrt{2}-\sqrt{3}-\sqrt{5}+c \sqrt{6}-\sqrt{7},$ where $a, b, c \in z$, then $a+b+c$ is equal to.........

  • A
    $21$
  • B
    $12$
  • C
    $29$
  • $23$

Answer

Correct option: D.
$23$
d
$ \int_0^3\left[x^2\right] d x+\int_0^3\left[\frac{x^2}{2}\right] d x $

$ =\int_0^1 0 d x+\int_1^{12} 1 d x+\int_{\sqrt{2}}^{\sqrt{3}} 2 d x$

$ +\int_{\sqrt{3}}^2 3 \mathrm{dx}+\int_2^{\sqrt{5}} 4 \mathrm{dx}+\int_{\sqrt{5}}^{\sqrt{6}} 5 \mathrm{dx} $

$ +\int_{\sqrt{6}}^{\sqrt{7}} 6 \mathrm{dx}+\int_{\sqrt{7}}^{\sqrt{8}} 7 \mathrm{dx}+\int_{\sqrt{8}}^3 8 \mathrm{dx} $

$ +\int_0^{\sqrt{2}} 0 \mathrm{dx}+\int_{\sqrt{2}}^2 1 \mathrm{dx} $

$ +\int_2^{\sqrt{6}} 2 \mathrm{dx}+\int_{\sqrt{6}}^{\sqrt{8}} 3 \mathrm{dx}+\int_{\sqrt{8}}^3 4 \mathrm{dx}=31-6 \sqrt{2}-\sqrt{3}-\sqrt{5} $

$ -2 \sqrt{6}-\sqrt{7} $

$ \mathrm{a}=31 \quad b=-6 \quad c=-2 $

$ \mathrm{a}+\mathrm{b}+\mathrm{c}=31-6-2=23$

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 ${1 \over {x(x + 1)\,(x + 2)....(x + n)}} = {{{A_0}} \over x} + {{{A_1}} \over {x + 1}} + {{{A_2}} \over {x + 2}} + .... + {{{A_n}} \over {x + n}}$ then ${A_r} = $
Let the mean and the standard deviation of the observation $2,3,3,4,5,7$, a, b be 4 and $\sqrt{2}$ respectively. Then the mean deviation about the mode of these observations is :
If $f(x) = \left\{ {\begin{array}{*{20}{c}}{{e^{\cos x}}\sin x,}&{|x|\, \le 2}\\{2,}&{{\rm{otherwise}}}\end{array}} \right.$, then $\int_{\, - \,2}^{\,3} {f(x)\,dx} $ is equal to
${\cos ^2}\left( {\frac{\pi }{6} + \theta } \right) - {\sin ^2}\left( {\frac{\pi }{6} - \theta } \right) = $
A ratio of the $5^{th}$ term from the beginning to the $5^{th}$ term from the end in the binomial expansion of $\left( {{2^{1/3}} + \frac{1}{{2{{\left( 3 \right)}^{1/3}}}}} \right)^{10}$ is
If the mean and variance of the frequency distribution

$x_i$ $2$ $4$ $6$ $8$ $10$ $12$ $14$ $16$
$f_i$ $4$ $4$ $\alpha$ $15$ $8$ $\beta$ $4$ $5$

are $9$ and $15.08$ respectively, then the value of $\alpha^2+\beta^2-\alpha \beta$ is $............$.

If ${S_k}$ denotes the sum of first $k$ terms of an arithmetic progression whose first term and common difference are $a$ and $d$ respectively, then ${S_{kn}}/{S_n}$ be independent of $n$ if
If $\vec u$ and $\vec v$ are unit vectors and $\theta$ is the acute angle between them, then $2 \vec u \times 3 \vec v$ is a unit vector for
If $x = {{\sqrt 5 + \sqrt 2 } \over {\sqrt 5 - \sqrt 2 }},y = {{\sqrt 5 - \sqrt 2 } \over {\sqrt 5 + \sqrt 2 }},$ then $3{x^2} + 4xy - 3{y^2} = $
Let $\frac{1}{{{x_1}}},\frac{1}{{{x_2}}},\frac{1}{{{x_3}}},.....,$  $({x_i} \ne \,0\,for\,\,i\, = 1,2,....,n)$  be in $A.P.$  such that  $x_1 = 4$ and $x_{21} = 20.$ If $n$  is the least positive integer for which $x_n > 50,$  then $\sum\limits_{i = 1}^n {\left( {\frac{1}{{{x_i}}}} \right)} $  is equal to.