MCQ
Let the function $f :[0,2] \rightarrow R$ be defined as$f(x)=\left\{\begin{array}{cc}e^{\min \left[x^2, x-[x]\right\}}, & x \in[0,1) \\e^{\left[x \log _e x\right]}, & x \in[1,2]\end{array}\right.$ where $[t]$ denotes the greatest integer less than or equal to $t.$ Then the value of the integral $\int \limits_0^2 x f(x) d x$ is
  • A
    $2 e -1$
  • B
    $1+\frac{3 e }{2}$
  • C
    $2 e -\frac{1}{2}$
  • D
    $(e-1)\left(e^2+\frac{1}{2}\right)$

Answer

Minimumm$ \left\{ x ^2,\{ x \}\right\}= x ^2 ; x \in[0,1)$
${\left[ x -\log _{ e } x \right]=1 ; x \in[1,2)}$
$\therefore f ( x )=\left\{\begin{array}{l} e ^{ x ^2} ; x \in[0,1) \\ e ; x \in[1,2)\end{array}\right.$
$\int \limits_0^2 x f(x) d x=\int \limits_0^1 x e^{x^2} d x+\int \limits_1^2 e x d x$
$=\frac{1}{2}( e -1)+\frac{1}{2}(4-1) e$
$=2 e -\frac{1}{2}$

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

Let the equations of two ellipses be ${E_1}:\,\frac{{{x^2}}}{3} + \frac{{{y^2}}}{2} = 1$ and ${E_2}:\,\frac{{{x^2}}}{16} + \frac{{{y^2}}}{b^2} = 1,$ If the product of their eccentricities is $\frac {1}{2},$ then the length of the minor axis of ellipse $E_2$ is
The area (in sq. units) in the first quadrant bounded by the parabola, $y = x^2 +1$, the tangent to it at the point $(2, 5)$ and the coordinate axes is
If $P_1$ and $P_2$ are two points on the ellipse  $\frac{{{x^2}}}{4} + {y^2} = 1$ at which the tangents are parallel to the chord joining the points $(0, 1)$ and $(2, 0)$, then the distance between $P_1$ and $P_2$ is
Set $A$ has $3$ elements and set $B$ has $4$ elements. The number of injection that can be defined from $A$ to $B$ is
If the system of equations  $2 x+3 y-z=5$  ;  $x+\alpha y+3 z=-4$  ;  $3 x-y+\beta z=7$ has infinitely many solutions, then $13 \alpha \beta$ is equal to
If $(1 - p)$ is a root of quadratic equation ${x^2} + px + (1 - p) = 0$ then its roots are
The triangle formed by the points $(0, 7, 10), (-1, 6, 6), (-4, 9, 6)$ is
If $\theta $ is the angle between the lines $AB$ and $CD$, then projection of line segment $AB$ on line $CD$, is
The area of the region bounded by the curves $y = |x - 2|,$ $x = 1,\,\,x = 3$ and the $x -$ axis is
If $A$ is a square matrix of order $3$ such that $ \operatorname{det}(\mathrm{A})=3 \text { and } $ $ \operatorname{det}\left(\operatorname{adj}\left(-4 \operatorname{adj}\left(-3 \operatorname{adj}\left(3 \operatorname{adj}\left((2 \mathrm{~A})^{-1}\right)\right)\right)\right)\right)=2^{\mathrm{m}} 3^{\mathrm{n}},$ then $m+\mid 2 n$ is equal to: