MCQ
$2{\tan ^{ - 1}}\frac{1}{3} + {\tan ^{ - 1}}\frac{1}{2} = $
  • A
    ${90^o}$
  • B
    ${60^o}$
  • C
    ${45^o}$
  • ${\tan ^{ - 1}}2$

Answer

Correct option: D.
${\tan ^{ - 1}}2$
d
(d) $2\,{\tan ^{ - 1}}\frac{1}{3} + {\tan ^{ - 1}}\frac{1}{2} = {\tan ^{ - 1}}\left( {\frac{{\frac{2}{3}}}{{1 - \frac{1}{9}}}} \right) + {\tan ^{ - 1}}\left( {\frac{1}{2}} \right)$
$ = {\tan ^{ - 1}}\left( {\frac{{\frac{2}{3}}}{{\frac{8}{9}}}} \right) + {\tan ^{ - 1}}\left( {\frac{1}{2}} \right) = {\tan ^{ - 1}}\,\left( {\frac{3}{4}} \right) + {\tan ^{ - 1}}\left( {\frac{1}{2}} \right)$
$ = {\tan ^{ - 1}}\left( {\frac{{\frac{1}{2} + \frac{3}{4}}}{{1 - \frac{1}{2} \times \frac{3}{4}}}} \right) = {\tan ^{ - 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 coefficient of $x^8$ in the expansion of $(x-1) (x- 2) (x-3)...............(x-10)$ is :
$\int\limits_{ - 1}^1 {\frac{{{x^4}}}{{1 + {e^{{x^7}}}}}dx\,}= $
If $f(x)\ =$ min. $\{1, x^2, x^3\},$ then
Let $A = \left[ {\begin{array}{*{20}{c}}
p&{13}\\
{ - 13}&p
\end{array}} \right]$ and $B = \left[ {\begin{array}{*{20}{c}}
{4q}&{85}\\
{ - 2}&1
\end{array}} \right]$  where  $p,q \in N$. It is given that $\left| A \right| = \left| B \right|$ and  $p,q \in[1,1000]$. Then total number of ordered pairs $(p,q)$ is
Consider a cuboid all of whose edges are integers and whose base is a square. Suppose the sum of all its edges is numerically equal to the sum of the areas of all its six faces. Then, the sum of all its edges is
Let $a, b, x$ be positive real numbers with $a \neq 1$, $x \neq 1$, ab $\neq 1$. Suppose $\log _{ a } b =10$, and $\frac{\log _{ a } x \log _{ x }\left(\frac{ b }{ a }\right)}{\log _{ x } b \log _{ ab } x }=\frac{ p }{ q }$, where $p$ and $q$ are positive integers which are coprime. Then $p+q$ is
If the straight line, $2x -3y + 17 = 0$ is perpendicular to the line passing through the points $(7, 17)$ and $(15, \beta )$, then $\beta $ equals:
If $\Delta = \left| {\,\begin{array}{*{20}{c}}{{a_1}}&{{b_1}}&{{c_1}}\\{{a_2}}&{{b_2}}&{{c_2}}\\{{a_3}}&{{b_3}}&{{c_3}}\end{array}\,} \right|$ and ${A_1},{B_1},{C_1}$denote the co-factors of ${a_1},{b_1},{c_1}$ respectively, then the value of the determinant $\left| {\begin{array}{*{20}{c}}{{A_1}}&{{B_1}}&{{C_1}}\\{{A_2}}&{{B_2}}&{{C_2}}\\{{A_3}}&{{B_3}}&{{C_3}}\end{array}} \right|$ is
Area bounded by the curve $y = \log x\,,$ $x - $ axis and the ordinates $x = 1,\,\,x = 2$ is
If $A = \left[ {\begin{array}{*{20}{c}}3&5\\2&0\end{array}} \right]$ and $B = \left[ {\begin{array}{*{20}{c}}1&{17}\\0&{ - 10}\end{array}} \right]$ then $|AB|$ is equal to