Question
Evaluate the following:
$\int\frac{\sqrt{1+\text{x}^2}}{\text{x}^4}\text{dx}$

Answer

Let $\text{I}=\int\frac{\sqrt{1+\text{x}^2}}{\text{x}^4}\text{dx}$ $=\int\frac{\sqrt{1+\text{x}^2}}{\text{x}}\cdot\frac{1}{\text{x}^3}\text{dx}$
$=\int\sqrt{\frac{1+\text{x}^2}{\text{x}^2}}\cdot\frac{1}{\text{x}^3}\text{dx}$ $=\int\sqrt{\frac{1}{\text{x}^2}+1}\cdot\frac{1}{\text{x}^3}\text{dx}$
Put $1+\frac{1}{\text{x}^2}=\text{t}^2\Rightarrow\frac{-2}{\text{x}^3}\text{dx}=2\text{tdt}$
$\Rightarrow-\frac{1}{\text{x}^3}=\text{tdt}$
$\therefore\ \text{I}=-\int\text{t}^2\text{dt}=-\frac{\text{t}^3}{3}+\text{C}$ $=-\frac{1}{3}\Big(1+\frac{1}{\text{x}^2}\Big)^{\frac{3}{2}}+\text{c}$

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

If $\vec{\text{a}}=2\hat{\text{i}}+2\hat{\text{j}}+3\hat{\text{k}},\vec{\text{b}}=-\hat{\text{i}}+2\hat{\text{j}}+\hat{\text{k}},$and $\vec{\text{c}}=3\hat{\text{i}}+\hat{\text{j}}$ are such that $\vec{\text{a}}+\lambda\vec{\text{b}}$ is perpendicular to $\vec{\text{c}},$ then find the value of $\lambda.$
Show that $\big|\vec{a}|\ \vec{b}+\big|\vec{b}\big|\ \vec{a}$ is perpendicular to $\big|\vec{a}|\ \vec{b}-\big|\vec{b}\big|\ \vec{a},$ for any two nonzero vectors $\vec{a}\ \text{and}\ \vec{b}.$
Evaluate $\int_{-\pi}^\pi(\cos a x-\sin b x)^2 d x$.
Find the angle between the line $\frac{\text{x}-2}{3}=\frac{\text{y}+1}{-1}=\frac{\text{z}-3}{2}$ and the plane 3x + 4y + z + 5 = 0
Evaluate the following integrals:
$\int\frac{\text{x}^6+1}{\text{x}^2+1}\text{dx}$
Find two positive integers whose sum is 16 and sum of whose cubes is minimum.
The money to be spent for the welfare of the employees of a firm is proportional to the rate of change of its total revenue (Marginal revenue). If the total revenue (in rupees) recieved from the sale of $x$ units of a product is given by $R(x) = 3x^2 + 36x + 5,$ find the marginal revenue, when $x = 5,$ and write which value does the question indicate.
Evaluate the following integrals:$\int\frac{\sin2\text{x}}{\sqrt{\cos^4\text{x}-\sin^2\text{x}+2}}\text{ dx}$
Differentiate w.r.t. x the function in Exercise:
$(\log\text{x})^{\log\text{x}},\text{x}>1$
Evaluate $\triangle=\begin{vmatrix}0&\sin\alpha&-\cos\alpha\\-\sin\alpha&0&\sin\beta\\\cos\alpha&-\sin\beta&0 \end{vmatrix}$