Question
Evaluate the following integrals:
$\int\frac{\text{x}^5}{\sqrt{1+\text{x}^2}}\text{ dx}$

Answer

$\text{I}=\int\frac{\text{x}^5}{\sqrt{1+\text{x}^2}}\text{ dx}\ ....(1)$ Let $1+\text{x}^3=\text{t}^2$ then, $\text{d}\big(1+\text{x}^3\big)=\text{d}\big(\text{t}^2\big)$ $\Rightarrow3\text{x}^2\text{dx}=\text{dt }2\text{t}$ $\Rightarrow\text{dx}=\frac{\text{dt}}{3\text{x}^2}\text{ 2}\text{t}$ Putting $1+\text{x}^3=\text{t}^2$ and $\text{dx}=\frac{2\text{t}}{3\text{x}^2}\text{ dt}$ in equation (1), we get,,$\text{I}=\int\frac{\text{x}^5}{\sqrt{{t}^2}}\times\frac{2\text{t}}{3\text{x}^2}\text{ dt}$
$=\int\frac{\text{x}^5}{\text{t}}\times\frac{2\text{t}}{3\text{x}^2}\text{ dt}$ $=\frac{2}{3}\int\text{x}^3\text{dt}$ $=\frac{2}{3}\int\big(\text{t}^2-1\big)\text{dt}$ $=\frac{2}{3}\times\frac{\text{t}^3}{3}-\frac{2}{3}\text{t}+\text{C}$ $\text{I}=\frac{2}{9}\big(1+\text{x}^3\big)^{\frac{3}{2}}-\frac{2}{3}\sqrt{1+\text{x}^3}+\text{C}$

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

A straight line is drawn through a given point $P(1, 4).$ Determine the least value of the sum of the intercepts on the coordinate axes.
Differentiate the following functions with respect to x:
$\tan^{-1}\Big\{\frac{\text{x}}{\sqrt{\text{a}^2-\text{x}^2}}\Big\},-\text{a}<\text{x}<\text{a}$
Evaluate:
$\int\frac{1}{\sin^{4}\text{x} +\sin^{2}\text{x}\cos^{2}\text{x}+\cos^{4}\text{x}}\text{dx}$
If $\text{A} = \begin{bmatrix}3&-4\\1&-1\end{bmatrix},$then prove that $\text{A}'' = \begin{bmatrix}1 + 2n & -4n \\n & 1 - 2n \end{bmatrix}$ where n is any positive integer.
Find the cartesian equation of a line passing through (1, -1, 2) and parallel to the line whose equation are $\frac{\text{x}-3}{1}=\frac{\text{y}-1}{2}=\frac{\text{z}+1}{-2}.$ Also, reduce the equation obtained in vector form.
Examine the continuity of function at $x=2$ and $x =3 . f(x)=|x-2|+|x-3|$
Three persons A, B and C apply for a job of Manager in a Private Company. Chances of their selection (A, B and C) are in the ratio $1 : 2 : 4$. The probabilities that A, B and C can introduce changes to improve profits of the company are $0.8, 0.5$ and $0.3$, respectively. If the change does not take place, find the probability that it is due to the appointment of C.
Find the points of local maxima or local minima and corresponding local maximum and local minimum values of the following functions. Also, find the points of inflection,
$\text{f}(\text{x})=\text{x}\sqrt{2-\text{x}^{2}}-\sqrt{2}\leq\text{x}\leq\sqrt{2}$
If either $\vec{a}=\vec{0}\ \ \text{or}\ \ \vec{b}=\vec{0},\ \ \text{then}\ \ \vec{a}\times\vec{b}=\vec{0}.$ Is the converse true? Justify your answer with an example.
$\int\limits_0^{\pi/4}\Bigg(\sqrt{\text{tan x}}+\sqrt{{\text{cot x}}}\Bigg)\text{ dx}=\sqrt{2}\cdot\frac{\pi}{2}$