MCQ
If from Lagrange's mean value theorem, we have
$\text{f}\ '(\text{x}_1)=\frac{\text{f}(\text{b})-\text{f}(\text{a})}{\text{b}-\text{a}},$ then:
  • A
    $\text{a}<\text{x}_1\leq\text{b}$
  • B
    $\text{a}\leq\text{x}_1<\text{b}$
  • $\text{a}<\text{x}_1<\text{b}$
  • D
    $\text{a}\leq\text{x}_1\leq\text{b}$

Answer

Correct option: C.
$\text{a}<\text{x}_1<\text{b}$
We have
$\text{f}(\text{x})=\text{x}+\frac{1}{\text{x}}=\frac{\text{x}^2+1}{\text{x}}$
In the Lagrange's mean value theorem, $\text{c}\in(\text{a},\text{b})$ such that $\text{f}\ '(\text{c})=\frac{\text{f}(\text{b})-\text{f}(\text{a})}{\text{b}-\text{a}}$
So, if there is $x_1$ such that $\text{f}\ '(\text{x}_1)=\frac{\text{f}(\text{b})-\text{f}(\text{a})}{\text{b}-\text{a}},$ then $\text{x}_1\in(\text{a},\text{b})$
$\Rightarrow\text{a}<\text{x}_1<\text{b}$

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

Find the cofactor of element $-3$ in the determinant $\triangle=\begin{bmatrix}1&4&4\\-3&5&9\\2&1&2\end{bmatrix}$ is:
Let $p$ denotes the probability that a man aged $x$ years will die in a year. The probability that out of $n$ men ${A_1},\,{A_2},\,{A_3}......{A_n}$each aged $x,\,\,{A_1}$will die in a year and will be the first to die, is
If $f(x) = {\mathop{\rm sgn}} \left( {3\cos x - \frac{a}{3}} \right)$ is continuous for all $x$, then the least positive integral values of $'a'$ is - (where sgn $(x)$ denotes signum function of $x$)
The area of the parallelogram whose adjacent sides are $i - k$ and $2j + 3k$ is
The area (in sq. units) of the region $\{(x,y):y^2 \geq 2x\,and\,x^2+y^2 \leq 4x,x \geq 0,y \leq 0 \}$ is
There are two value of a which makes the determinant $\triangle=\begin{vmatrix}1&-2&5\\2&\text{a}&-1\\0&4&2\text{a}\end{vmatrix}$ equal to $86$. The sum of these two values is:
Let $\vec{a}=6 \hat{i}+\hat{j}-\hat{k}$ and $\vec{b}=\hat{i}+\hat{j}$. If $\vec{c}$ is a is vector such that $|\vec{c}| \geq 6, \vec{a} \cdot \vec{c}=6|\vec{c}|,|\vec{c}-\vec{a}|=2 \sqrt{2}$ and the angle between $\vec{a} \times \vec{b}$ and $\vec{c}$ is $60^{\circ}$, then $|(\vec{a} \times \vec{b}) \times \vec{c}|$ is equal to:
The angle between a line with direction ratios $2 : 2 : 1$ and a line joining $(3, 1, 4)$ to $(7, 2, 12)$ is
$\int_0^{\pi /2} {{{\sin }^{2m}}x\,dx = } $
Given that $A$ is a square matrix of order $3$ and $|A| = -4,$ then $|\operatorname{ad}| A \mid$ is equal to :