MCQ
If $I=\int\limits_{1}^{2} \frac{d x}{\sqrt{2 x^{3}-9 x^{2}+12 x+4}},$ then
  • $\frac{1}{9} < I^{2} < \frac{1}{8}$
  • B
    $\frac{1}{3} < I^{2} < \frac{1}{2}$
  • C
    $\frac{1}{9} < I < \frac{1}{8}$
  • D
    $\frac{1}{3} < I < \frac{1}{2}$

Answer

Correct option: A.
$\frac{1}{9} < I^{2} < \frac{1}{8}$
a
$f(x)=\frac{1}{\sqrt{2 x^{3}-9 x^{2}+12 x+4}}$

$f^{\prime}(x)=\frac{-6(x-1)(x-2)}{2\left(2 x^{3}-9 x^{2}+12 x+4\right)^{3 / 2}}$

$\therefore f(\mathrm{x})$ is decreasing in $(1,2)$

$f(1)=\frac{1}{3} ; f(2)=\frac{1}{\sqrt{8}}$

$\frac{1}{3}<\mathrm{I}<\frac{1}{\sqrt{8}}$$\Rightarrow \mathrm{I}^{2} \in\left(\frac{1}{9}, \frac{1}{8}\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

A line passes through the point $(3, 4)$ and cuts off intercepts from the coordinates axes such that their sum is $14.$ The equation of the line is
A coin is tossed $3$ times by $2$ persons. What is the probability that both get equal number of heads
If $A$ is the $A.M.$ of the roots of the equation ${x^2} - 2ax + b = 0$ and $G$ is the $G.M.$ of the roots of the equation ${x^2} - 2bx + {a^2} = 0,$ then
The radius of a cylinder is increasing at the rate of $3\,\,m/sec$ and its altitude is decreasing at the rate of $4 \,m/sec$. The rate of change of volume when radius is  $ 4 $ metres and altitude is  $6 $ metres is
Let a be the sum of all coefficients in the expansion of $\left(1-2 x+2 x^2\right)^{2023}\left(3-4 x^2+2 x^3\right)^{2024}$and $b=\lim _{x \rightarrow 0}\left(\frac{\int_0^x \frac{\log (1+t)}{t^{2024}+1} d t}{x^2}\right)$. If the equations $cx ^2+ dx + e =0$ and $2 bx ^2+ ax +4=0$ have a common root, where $c, d, e \in R,$ then $d : c : e$ equals
If $x = {\log _5}(1000)$ and $y = {\log _7}(2058)$ then
In how many ways can $21$ English and  $19$ Hindi books be placed in a row so that no two Hindi books are together
The number of ways five alphabets can be chosen from the alphabets of the word $\text{MATHEMATICS},$ where the chosen alphabets are not necessarily distinct, is equal to :
If $|z - 2|/|z - 3| = 2$ represents a circle, then its radius is equal to
The locus of a point $P (h, k)$ such that the line $y = hx + k$ is tangent to $4x^2 - 3y^2 = 1$ , is a/an