Question
Prove that:
$2\sin^{-1}\frac{3}{5}=\tan^{-1}\frac{24}{7}$

Answer

$\text{Let} \sin^{-1}\frac{3}{5}=x. \text{Then}, \sin x=\frac{3}{5}.$ $\Rightarrow\cos x=\sqrt{1-\bigg(\frac{3}{5}\bigg)^2}=\frac{4}{5}$ $\therefore\tan x=\frac{3}{4}$ $\therefore x=\tan^{-1}\frac{3}{4}\Rightarrow\sin^{-1}\frac{3}{5}=\tan^{-1}\frac{3}{4}$ Now, we have: $\text{L.H.S.}=2\sin^{-1}\frac{3}{5}=2\tan^{-1}\frac{3}{4}$$=\tan^{-1}\Bigg(\frac{2\times\frac{3}{4}}{1-\left(\frac{3}{4}\right)^2}\Bigg)$ $\bigg[2\tan^{-1}x=\tan^{-1}\frac{2x}{1-x^2}\bigg]$
$=\tan^{-1}\Bigg(\frac{\frac{3}{2}}{\frac{16-9}{16}}\Bigg)=\tan^{-1}\bigg(\frac{3}{2}\times\frac{16}{7}\bigg)$
$=\tan^{-1}\frac{24}{7}=\text{R.H.S.}$

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

Evaluate the following integrals:$\int\text{x}^2\text{e}^{-\text{x}}\text{dx}$
If $\text{A}=\begin{bmatrix}\cos\text{x}&\sin\text{x}\\-\sin\text{x}&\cos\text{x}\end{bmatrix},$ find $x$ satisfying $0<\text{x}<\frac{\pi}{2}$ when $A + A^T = I$
An urn contains four white and three red balls. Find the probability distribution of the number of red balls in three draws with replacement from the urn.
Solve the following differential equation:$x \cos \text{y dy} = ( xe^{x} \log x + e^{x}) dx$
 
Show that the relation $R$ defined in the set A of all polygons as $R = (P_1, P_2) : P_1$ and $P_2$ have same number of sides, is an equivalence relation. What is the set of all elements in A related to the right angle triangle $T$ with sides $3, 4,$ and $5?$
Integrate the rational function $\frac{x^{3}+x+1}{x^{2}-1}$
For any two vectors $\vec{\text{a}}$ and $\vec{\text{b}},$ prove that $\big|\vec{\text{a}}\times\vec{\text{b}}\big|^2=\begin{vmatrix}\vec{\text{a}}.\vec{\text{a}}&\vec{\text{a}}.\vec{\text{b}}\\\vec{\text{b}}.\vec{\text{a}}&\vec{\text{b}} .\vec{\text{b}}\end{vmatrix}.$
Differentiate the following functions with respect to x:
$\text{e}^{\sin\sqrt{\text{x}}}$
Evaluate the following integrals:
$\int\frac{3\text{x}^5}{1+\text{x}^{12}}\text{dx}$
Find a vector of magnitude of 5 units parallel to the resultant of the vectors $\vec{\text{a}}=2\hat{\text{i}}+3\hat{\text{j}}-\hat{\text{k}}$ and $\vec{\text{b}}=\hat{\text{i}}-2\hat{\text{j}}+\hat{\text{k}}$.