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

Answer

Let $\text{I}=\int\frac{\text{x}+1}{\sqrt{\text{x}^2+1}}\text{dx}$
let $\text{x}+1=\lambda\frac{\text{d}}{\text{dx}}(\text{x}^2+1)+\mu$
$\text{x}+1=\lambda(2\text{x})+\mu$
Compairing the coefficient of like powewrs of x,
$2\lambda=1\ \Rightarrow\lambda=\frac{1}{2}$
$\Rightarrow\mu=1$
So, $\text{I}=\int\frac{\frac{1}{2}(2\text{x})+1}{\sqrt{\text{x}^2+1}}\text{dx}$
$=\frac{1}{2}\int\frac{(2\text{x})}{\sqrt{\text{x}^2+1}}\text{dx}+\int\frac{1}{\sqrt{\text{x}^2+1}}\text{dx}$
$\text{I}=\frac{1}{2}\times2\sqrt{\text{x}^2+1}+\log\big|\text{x}+\sqrt{\text{x}^2+1}\big|+\text{C}$ $\big[\text{since}, \int\frac{1}{\sqrt{\text{x}}}\text{dx}=2\sqrt{\text{x}}+\text{c},\int\frac{1}{\sqrt{\text{x}^2+1}}\text{dx}=\log\big|\text{x}+\sqrt{\text{x}^2-\text{x}^2}\big|+\text{C}\big]$
$\text{I}=\sqrt{\text{x}^2+1}+\log\big|\text{x}+\sqrt{\text{x}^2+1}\big|+\text{C}$

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

Find the length and the foot of perpendicular from the poin $\Big(1,\frac{3}{2},2\Big)$ to the plane 2x - 2y + 4z + 5 = 0.
Discuss the continuity of $\text{f(x)}=\sin|\text{x}|$
If $\text{y}=(\sin\text{x})^{(\sin\text{x})^{(\sin\text{x})^{....\infty}}},$ prove that $\frac{\text{y}^2\cot\text{x}}{(1-\text{y}\log\sin\text{x})}$
The height of a cone increases by k%, its semi-vertical angle remaining the same. What is the approximate percentage increase
  1. In total surface area, and
  2. In the volume, assuming that k is small?
If $\big|\vec{\text{a}}+\vec{\text{b}}\big|=60,\big|\vec{\text{a}}-\vec{\text{b}}\big|=40$ and $\big|\vec{\text{b}}\big|=46,$ find $|\vec{\text{a}}|$
Solve the follwing system of equations by matrix method:
$5x + 2y = 3$
$3x + 2y = 5$
Find the equation of the perpendicular drawn from the point P(-1, 3, 2) to the line $\vec{\text{r}}=\big(2\hat{\text{j}}+3\hat{\text{k}}\big)+\lambda\big(2\hat{\text{i}}+\hat{\text{j}}+3\hat{\text{k}}\big).$ Also, find the coordinates of the foot of the perpendicular from P.
Find the equation of tangent to the curve $x = \sin 3_{t}, y = \cos 2_{t}, \text{at, t} = \frac{\pi}{4} $
A small firm manufactures gold rings and chains. The total number of rings and chains manufactured per day is at most 24. It takes 1 hour to make a ring and 30 minutes to make a chain. The maximum number of hours available per day is 16. If the profit on a ring is Rs. 300 and that on a chain is Rs. 190, find the number of rings and chains that should be manufactured per day, so as to earn the maximum profit. Make it as an LPP and solve it graphically.
Evaluate the following integrals:
$\int\limits^\pi_0\Big(\frac{\text{x}}{1+\sin^2\text{x}}+\cos^7\text{x}\Big)\text{dx}$