Question
Evaluate the following integrals:$\int\cos^{-1}\Big(\frac{1-\text{x}^2}{1+\text{x}^2}\Big)\text{dx}$

Answer

Let $\text{I}=\int\cos^{-1}\Big(\frac{1-\text{x}^2}{1+\text{x}^2}\Big)\text{dx}$
Let $\text{x}=\tan\text{t}$
$\text{dx}=\sec^2\text{t dt}$
$\text{I}=\int\cos^{-1}\Big(\frac{1-\tan^2\text{t}}{1+\tan^2\text{t}}\Big)\sec^2\text{t dt}$
$=\int\cos^{-1}(\cos2\text{t})\sec^2\text{t dt}$
$=\int2\text{t}\sec^2\text{x dx}$
$=2\Big[\text{t}\int\sec^2\text{t dt}-\int(1\int\sec^2\text{t dt})\text{dt}\Big]$
$=2[\text{t}\tan^2\text{t}-\int\tan\text{t dt}]$
$=2[\text{t}\tan^2\text{t}-\log\sec\text{t}]+\text{C}$
$=2\Big[\text{x}\tan^{-1}\text{x}-\log\sqrt{1+\text{x}^2}\Big]+\text{C}$
$\text{I}=2\text{x}\tan^{-1}\text{x}-\log|1+\text{x}^2|+\text{C}$

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

Solve the following LPP graphically:
Maximise Z = 1000x + 600y
subject to the constraints
$\text{ }\text{x + y} \leq 200\\ \text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{x} \geq 20\\ \text{ }\text{ }\text{ }\text{ }\text{y - 4x} \geq 0\\ \text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{ }\text{x, y} \geq 0. $
The population of a village increases continuously at the rate proportional to the number of its inhabitants present at any time. If the population of the village was $20, 000$ in $1999$ and $25000$ in the year $2004,$ what will be the population of the village in $2009?$
Find the shortest distance between the following pairs of lines whose vector equations are:
$\vec{\text{r}}=(1-\text{t})\hat{\text{i}}+(\text{t}-2)\hat{\text{j}}+(3-\text{t})\hat{\text{k}}$ and $\vec{\text{r}}=(\text{s}+1)\hat{\text{i}}+(2\text{s}-1)\hat{\text{j}}-(2\text{s}+1)\hat{\text{k}}$
A fair coin is tossed four times. Let X denote the longest string of heads accuring. Find the probability distribution mean and variance of X.
Find the area, lying above $x-$axis and included between the circle $x^2 + y^2 = 8x$ and the parabola $y^2 = 4x.$
Prove by vector method that the internal bisectors of the angles of a triangle are concurrent.
Discuss the applicability of Lagrange's mean value theorem for the function:
f(x) = |x| on [−1, 1]
If $f(x) = Ax^2 + Bx + C$ is such that $f(a) = f(b),$ then write the value of $c$ in Rolle's theorem.
A firm manufactures two products $A$ and $B.$ Each product is processed on two machines $M_1$ and $M_2.$ Product $A$ requires $4$ minutes of processing time on $M_1$ and $8$ min. on $M_2;$ product $B$ requires $4$ minutes on $M_1$ and $4$ min. on $M_2.$ The machine $M_1$ is available for not more than $8$ hrs $20$ min. while machine $M_2$ is available for $10$ hrs. during any working day. The products $A$ and $B$ are sold at a profit of $Rs. 3$ and $Rs. 4$ respectively.
Formulate the problem as a linear programming problem and find how many products of each type should be produced by the firm each day in order to get maximum profit.
Give examples of two surjective functions $f_1$ and $f_2$ from $Z$ to $Z$ such that $f_1 + f_2$ is not surjective.