Question
Evaluate the following integrals:$\int\frac{1}{\sqrt{7-6\text{x}-\text{x}^2}}\text{ dx}$

Answer

$7 - 6x - x^2$ can be written as $7 - (x^2 + 6x + 9 - 9).$
Therefore,$7-(\text{x}^2+6\text{x}+9-9)$
$=16-(\text{x}^2+6\text{x}+9)$ $=16-(\text{x}+3)^2$ $=(4)^2-(\text{x}+3)^2$
$\therefore\ \int\frac{1}{\sqrt{7-6\text{x}-\text{x}^2}}\text{ dx}$ $=\int\frac{1}{\sqrt{(4)^2-(\text{x}+3)^2}}\text{ dx}$
Let $x + 3 = t$
$\Rightarrow\text{dx}=\text{dt}$
$\Rightarrow\int\frac{1}{\sqrt{(4)^2-(\text{x}+3)^2}}\text{ dx}$
$=\int\frac{1}{\sqrt{(4)^2-(\text{t})^2}}\text{ dt}$
$=\sin^{-1}\Big(\frac{\text{t}}{4}\Big)+\text{C}$
$=\sin^{-1}\Big(\frac{\text{x}+3}{4}\Big)+\text{C}$

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

Evaluvate the following intregals:
$\int\frac{8\cot\text{x}+1}{3\cot\text{x}+2}\ \text{dx}$
A(1, 0, 4) B(0, -11, 1), C(2, -3, 1) are three points and D is the fool of perpendicular from A on BC. Find the coordinates of D.
In a game, a man wins ₹ 5 for getting a number greater than 4 and loses ₹ 1 otherwise, when a fair die is thrown. The man decided to throw a die three but to quit as and when he gets a number greater than 4. Find the expected value of the amount he wins/loses.
The bag $A$ contains $8$ white and $7$ black balls while the bag $B$ contains $5$ white and $4$ black balls. One ball is randomly picked up from the bag $A$ and mixed up with the balls in bag $B$. Then a ball is randomly drawn out from it. Find the probability that ball drawn is white.
Find the cartesian form of the equations of the following planes.
$\vec{\text{r}}=(\hat{\text{i}}-\hat{\text{j}})+\text{s}(-\hat{\text{i}}+\hat{\text{j}}+2\hat{\text{k}})+\text{t}(\hat{\text{i}}+2\hat{\text{j}}+\hat{\text{k}})$ 
If a young man drives his vehicle at 25 km/hr, he has to spend Rs. 2 per km on petrol. If he drives it at a faster speed of 40 km/hr, the petrol cost increases to Rs. 5 per km. He has Rs. 100 to spend on petrol and travel within one hour. Express this as an LPP and solve the same.
Solve the following differential equation:
$\frac{\text{dy}}{\text{dx}}+\text{y}\tan\text{x}=\cos\text{x}$
Find the angle between the lines whose direction cosines are given by the equations: $l + m +n = 0$ and $l^2 + m^2 + n^2 = 0$
A dietician wishes to mix together two kinds of food $X$ and $Y$ in such a way that the mixture contains at least $10$ units of vitamin $A, 12$ units of vitamin $B$ and $8$ units of vitamin $C.$ The vitamin contents of one $\ kg$ food is given below:
Food
Vitamin $A$
Vitamin $B$
Vitamin $C$
$X$ $1$ $2$ $3$
$Y$ $2$ $2$ $1$
One $\ kg$ of food $X$ costs $Rs. 16$ and one $\ kg$ of food $Y$ costs $Rs. 20.$ Find the least cost of the mixture which will produce the required diet?
Find the equation of the line passing through the points $(1, -1, 1)$ and perpendicular to the lines joining the points $(4, 3, 2), (1, -1, 0)$ and $(1, 2, -1) (2, 1, 1).$