MCQ
Find the value of $\tan ^{-1}\left(2 \cos \left(2 \sin ^{-1} \frac{1}{2}\right)\right)$.
  • A
    $\frac{\pi}{3}$
  • $\frac{\pi}{4}$
  • C
    $\frac{\pi}{2}$
  • D
    $\frac{\pi}{6}$

Answer

Correct option: B.
$\frac{\pi}{4}$
We have,
$\tan ^{-1}\left\{2 \cos \left(2 \sin ^{-1}\left(\frac{1}{2}\right)\right)\right\}=\tan ^{-1}\left\{2 \cos \left(2 \times \frac{\pi}{6}\right)\right\}$
$=\tan ^{-1}\left\{2 \cos \frac{\pi}{3}\right\}=\tan ^{-1}\left[2 \times \frac{1}{2}\right]=\tan ^{-1} 1=\frac{\pi}{4}$

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 constraints $-x+y \leq 1,-x+3 y \leq 9, x \geq 0, y \geq 0$ defines on $.....$
If $y = x + {1 \over x}$, then
If $q_1$ , $q_2$ , $q_3$ are roots of the equation $x^3 + 64$ = $0$ , then the value of $\left| {\begin{array}{*{20}{c}}
  {{q_1}}&{{q_2}}&{{q_3}} \\ 
  {{q_2}}&{{q_3}}&{{q_1}} \\ 
  {{q_3}}&{{q_1}}&{{q_2}} 
\end{array}} \right|$ is
If $x = a(\cos \theta + \theta \sin \theta )$, $y = a(\sin \theta - \theta \cos \theta ),{\rm{ }}$ then ${{dy} \over {dx}} = $
$\int {\frac{{x\,\,dx}}{{{x^2} + 4x + 5}} = } $
If $x, y, z$ are non$-$zero real numbers, then the inverse, then the inverse of the matrix $\begin{bmatrix}\text{x} & 0 & 0\\ 0 & \text{y} & 0 \\ 0 & 0 & \text{z}\end{bmatrix},$ is:
If the system of equations $x + ay = 0,$ $az + y = 0$ and $ax + z = 0$ has infinite solutions, then the value of $a$ is
If $\left[\begin{array}{ccc}x+3 & z+4 & 2 y-7 \\ -6 & a-1 & 0 \\ b-3 & -21 & 0\end{array}\right]=\left[\begin{array}{ccc}0 & 6 & 3 y-2 \\ -6 & -3 & 2 c+2 \\ 2 b+4 & -21 & 0\end{array}\right]$ then find the values of $a,\, b, \,c, \,x, \,y$ and $z$.
The equation of the curve whose slope is given by $\frac{\text{dy}}{\text{dx}}=\frac{2\text{y}}{\text{x}};\text{x}>0,\text{y}>0$ and which passes through the point (1, 1) is:
A function is matched below against an interval where it is supposed to be increasing. Which of the following pairs is incorrectly matched 

           Interval                                                        Function