MCQ
If $y = {\tan ^{ - 1}}(\sec x - \tan x)$ then ${{dy} \over {dx}} = $
  • A
    $2$
  • $ -0.5$
  • C
    $\frac{1}{2}$
  • D
    $-2$

Answer

Correct option: B.
$ -0.5$
b
(b) $y = {\tan ^{ - 1}}(\sec x - \tan x)$

$\frac{{dy}}{{dx}} = \frac{1}{{1 + {{(\sec x - \tan x)}^2}}}(\sec x\tan x - {\sec ^2}x)$

$\frac{{dy}}{{dx}} = \frac{{{{\cos }^2}x.{{\sec }^2}x(\sin x - 1)}}{{{{(1 - \sin x)}^2} + {{\cos }^2}x}}$

$\frac{{dy}}{{dx}} = \frac{{\sin x - 1}}{{1 - 2\sin x + {{\sin }^2}x + {{\cos }^2}x}} $

$= \frac{{\sin x - 1}}{{2(1 - \sin x)}} = - \frac{1}{2}.$

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

The sum of the series

$\frac{3}{{1! + 2! + 3!}} + \frac{4}{{2! + 3! + 4!}} + \frac{5}{{3! + 4! + 5!}} + ...... + \frac{{2008}}{{\left( {2006} \right)! + \left( {2007} \right)! + \left( {2008} \right)!}}$ is equal to

If $x = \frac{{n\pi }}{2}$ , satisfies the equation $sin\, \frac{x}{2}- cos \frac{x}{2} = 1 - \sin\, x \&$ the inequality $\left| {\frac{x}{2}\,\, - \,\,\frac{\pi }{2}} \right|\,\, \le \,\,\frac{{3\pi }}{4}$, then:
Common roots of the equations $2{\sin ^2}x + {\sin ^2}2x = 2$ and $\sin 2x + \cos 2x = \tan x,$ are
Let for two distinct values of $p$ the lines $y=x+p$ touch the ellipse E : $\frac{x^2}{4^2}+\frac{y^2}{3^2}=1$ at the points A and B. Let the line $y = x$ intersect $E$ at the points $C$ and $D$. Then the area of the quadrilateral $A B C D$ is equal to
The sum of infinite series ${\tan ^{ - 1}}\left( {\frac{2}{{1 - {1^2} + {1^4}}}} \right) + {\tan ^{ - 1}}\left( {\frac{4}{{1 - {2^2} + {2^4}}}} \right) + {\tan ^{ - 1}}\left( {\frac{6}{{1 - {3^2} + {3^4}}}} \right) + .....$ is
Suppose $X$ follows a binomial distribution with parameters $n$ and $p$, where $0 < p < 1.$ If $\frac{{P\,(X = r)}}{{P\,(X = n - r)}}$ is independent of $n$ and $r$, then
The locus of a point $P\left( {\alpha ,\beta } \right)$ moving under the condition that the line $y = \alpha x + \beta $ is a tangent to the hyperbola $\frac{{{x^2}}}{{{a^2}}} - \frac{{{y^2}}}{{{b^2}}} = 1$ is
Let $y=y(x)$ be solution of the differential equation $\log _{e}\left(\frac{d y}{d x}\right)=3 x+4 y$, with $y(0)=0$. If $y\left(-\frac{2}{3} \log _{e} 2\right)=\alpha \log _{e} 2$, then the value of $\alpha$ is equal to:
If the variance of the frequency distribution is $160$ , then the value of $\mathrm{c} \in \mathrm{N}$ is
$X$ $c$ $2c$ $3c$ $4c$ $5c$ $6c$
$f$ $2$ $1$ $1$ $1$ $1$ $1$
Let $\vec{a}=\vec{i}-\alpha \vec{j}+\beta \hat{k}, \vec{b}=3 \hat{i}+\beta \hat{j}-\alpha \hat{k}$ and $\vec{c}=-\alpha \hat{i}-2 \hat{j}+\hat{k}$, where $\alpha$ and $\beta$ are integers. If $\vec{a} \cdot \vec{b}=-1$ and $\overrightarrow{\mathrm{b}} \cdot \overrightarrow{\mathrm{c}}=10$, then $(\overrightarrow{\mathrm{a}} \times \overrightarrow{\mathrm{b}}) \cdot \overrightarrow{\mathrm{c}}$ is equal to $.....$