Question
Write the value of $\tan\Big(2\tan^{-1}\frac{1}{5}\Big)$

Answer

Let $\tan\theta=\frac{1}{5}$$\tan\Big(2\tan^{-1}\frac{1}{5}\Big)$
$=\tan2\theta$
$=\frac{2\tan\theta}{1-\tan^2\theta}$
$=\frac{2\times\frac{1}{5}}{1-\frac{1}{25}}$
$=\frac{\frac{2}{5}}{\frac{24}{25}}$
$=\frac{5}{12}$

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

Find x, y, a and b if $\begin{bmatrix}3\text{x}+4\text{y}&2&\text{x}-2\text{y}\\\text{a}+\text{b}&2\text{a}-\text{b}&^-1\end{bmatrix}=\begin{bmatrix}2&2&4\\5&-5&-1\end{bmatrix}$
Determine the order and degree of the following differential equations. state also whether they are linear or non linear.
$\frac{\text{d}^4\text{y}}{\text{dx}^4}=\Big\{\text{c}+\Big(\frac{\text{dy}}{\text{dx}}\Big)^2\Big\}^{\frac{3}{2}}$
Find the Cartesian equations of the line which passes through the point (-2, 4, -5) and is parallel to the line $\frac{\text{x}+3}{3}=\frac{4-\text{y}}{5}=\frac{\text{z}+8}{6}.$
Let $\text{f}:\Big[-\frac{\pi}{2},\frac{\pi}{2}\Big]\rightarrow\ \text{A}$ be defined by f(x)= sinx. If f is a bijection, write set A.
Define an equivalence relation.
Evaluate the following integral:
$\int\frac{1}{\sqrt{\text{a}^2-\text{b}^2\text{x}^2}}\text{ dx}$
Discuss the continuity of the following functions at the indicated point:
$\text{f}\text{(x)}=\begin{cases}\text{(x}-\text{a})\sin\Big(\frac{1}{\text{x}-\text{a}}\Big), & \text{x} \neq 0\\\ \ 0, & \text{x} = \text{a}\end{cases}\text{at x}=\text{a}$
Show that the following triads of vectors are coplanar:
$\vec{\text{a}}=\hat{\text{i}}+2\hat{\text{j}}-\hat{\text{k}},\vec{\text{b}}=3\hat{\text{i}}+2\hat{\text{j}}+7\hat{\text{k}},\vec{\text{c}}=5\hat{\text{i}}+6\hat{\text{j}}+5\hat{\text{k}}$
Find x, y, z and t, if.
$3\begin{bmatrix}\text{x}&\text{y}\\\text{z}&\text{t}\end{bmatrix}=\begin{bmatrix}\text{x}&6\\-1&2\text{t}\end{bmatrix}+\begin{bmatrix}4&\text{x}+\text{y}\\\text{z}+\text{t}&3\end{bmatrix}$
For the principal values of the following:
$\cot^{-1}\Big(-\sqrt3\Big)$