MCQ
${\cot ^{ - 1}}\frac{3}{4} + {\sin ^{ - 1}}\frac{5}{{13}} = $
  • ${\sin ^{ - 1}}\frac{{63}}{{65}}$
  • B
    ${\sin ^{ - 1}}\frac{{12}}{{13}}$
  • C
    ${\sin ^{ - 1}}\frac{{65}}{{68}}$
  • D
    ${\sin ^{ - 1}}\frac{5}{{12}}$

Answer

Correct option: A.
${\sin ^{ - 1}}\frac{{63}}{{65}}$
a
(a) Let ${\cot ^{ - 1}}\frac{3}{4} = \theta \,\, \Rightarrow \,\,\cot \theta = \frac{3}{4}$

and $\sin \theta = \frac{1}{{\sqrt {1 + {{\cot }^2}\theta } }} = \frac{1}{{\sqrt {1 + (9/16)} }} = \frac{4}{5}$

Hence ${\cot ^{ - 1}}\frac{3}{4} + {\sin ^{ - 1}}\frac{5}{{13}} = {\sin ^{ - 1}}\frac{4}{5} + {\sin ^{ - 1}}\frac{5}{{13}}$

$ = {\sin ^{ - 1}}\left[ {\frac{4}{5}.\sqrt {1 - \frac{{25}}{{169}}} + \frac{5}{{13}}.\,\sqrt {1 - \frac{{16}}{{25}}} } \right]$

$ = {\sin ^{ - 1}}\left[ {\frac{4}{5}.\frac{{12}}{{13}} + \frac{5}{{13}}.\frac{3}{5}} \right]$

$ = {\sin ^{ - 1}}\left[ {\frac{{48 + 15}}{{65}}} \right] = {\sin ^{ - 1}}\frac{{63}}{{65}}$.

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 value of $\lambda$ for which two vectors $2 \hat{i}-\hat{j}+2 \hat{k}$ and $3 \hat{i}+\lambda \hat{j}+\hat{k}$ are perpendicular is
Area bounded by curves $x =\sqrt {y -1}$ and $y = x + 1$ is-
If $A = \left[ {\begin{array}{*{20}{c}}0&i\\{ - i}&0\end{array}} \right]$, then the value of ${A^{40}}$ is
Choose the correct answer
If $\theta$ is the angle between any two vectors $\vec{\text{a}}\ \text{and}\ \vec{\text{b}}, \text{then}\ |\vec{\text{a}}\cdot\vec{\text{b}}|=|\vec{\text{a}}\times\vec{\text{b}}|\ \text{when}\ \theta$ is equal to
Let $A=\{1,2,3,4,5\}$ and $B=\{1,2,3,4,5,6\}$. Then the number of functions $f: A \rightarrow B$ satisfying $f(1)+f(2)=f(4)-1$ is equal to
If abscissa of vertex of parabola $y = a{x^2} + bx + c$ is $1\left( {a,b,c > 0} \right)$ and $f(x) = \int\limits_0^x {\left( {3a{x^2} + bx + c} \right)dx} $ is strictly increasing function $\forall \,\,\,x\, \in \,R$ , then maximum possible value of $\left[ {\frac{a}{c}} \right]$ is (where [.] denotes greatest integer function)
Let $\text{f(x)}=\begin{vmatrix}\cos\text{x}&\text{x}&1\\2\sin\text{x}&\text{x}&2\text{x}\\\sin\text{x}&\text{x}&\text{x}\end{vmatrix},$ then $\lim_\limits{\text{x}\rightarrow0}\frac{\text{f(x)}}{\text{x}^2}$ is equal to:
The area of the parallelogram whose diagonals are $a = 3\,i + j - 2k$ and $b = i - 3\,j + 4\,k$ is
If $\text{y}=2\sin\text{x}+\sin2\text{x}$ for $0\leq \text{x}\leq 2\pi,$ then the area enclosed by the curve and $x-$ axis is :
The area of the region bounded by the curve $x^2=4 y$ and the straight line $x=4 y-2$ is: