Skip to main content

What is the integration of log (1+x^2)?

Use integration by part to solve this question.

\[% \color{red}{\boxed{\color{blue}{\boxed{\color{black}{\text{ Using integration by parts, we have}\\\displaystyle \quad \int \ln \left(1+x^{2}\right) d x\\\displaystyle =x \ln \left(1+x^{2}\right)-\int x \frac{2 x}{1+x^{2}} d x \\\displaystyle =x \ln \left(1+x^{2}\right)-2 \int\left(1-\frac{1}{1+x^{2}}\right) d x \\\displaystyle =x \ln \left(1+x^{2}\right)-2 x+2 \tan ^{-1} x+C}}}}} \]

Comments

Popular posts from this blog

Parabola - Notes, Concept and All Important Formula

PARABOLA 1. CONIC SECTIONS : A conic section, or conic is the locus of a point which moves in a plane so that its distance from a fixed point is in a constant ratio to its perpendicular distance from a fixed straight line. (a) The fixed point is called the FOCUS. (b) The fixed straight line is called the DIRECTRIX. (c) The constant ratio is called the ECCENTRICITY denoted by e. (d) The line passing through the focus & perpendicular to the directrix is called the AXIS. (e) A point of intersection of a conic with its axis is called a VERTEX. All Chapter Notes, Concept and Important Formula 2. GENERAL EQUATION OF A CONIC : FOCAL DIRECTRIX PROPERTY: The general equation of a conic with focus \((p, q) \) & directrix \(\mathrm{lx}+\mathrm{my}+\mathrm{n}=0\)   is :  \(\left(1^{2}+\mathrm{m}^{2}\right)\left[(x-\mathrm{p})^{2}+(\mathrm{y}-\mathrm{q})^{2}\right] \) \(=e^{2}(\mathrm{l} \mathrm{x}+\mathrm{m} y+\mathrm{n})^{2}  \) \(\equiv \mathrm{ax}^{2}+2 \mathrm{~h} ...

Complex Number - Notes, Concept and All Important Formula

COMPLEX NUMBER 1. DEFINITION : Complex numbers are defined as expressions of the form \(a + ib\) where \(a, b \in R \quad \& i=\sqrt{-1}\) . It is denoted by \(z\) i.e. \(z=a+i b\) . 'a' is called real part of \(z(a=R e z)\) and ' \(b\) ' is called imaginary part of \(z(b=\operatorname{Im} z)\) Note : (i) The set \(R\) of real numbers is a proper subset of the Complex Numbers. Hence the Complex Number system is \(N \subset W \subset I \subset Q \subset R \subset C\) (ii) Zero is both purely real as well as purely imaginary but not imaginary. (iii) \(i =\sqrt{-1}\) is called the imaginary unit. Also \(i ^{2}=-1 ;\, i ^{3}=- i\) ; \(i ^{4}=1\) etc. (iv) \(\sqrt{a} \sqrt{b}=\sqrt{a b}\) only if atleast one of a or \(b\) is non-negative. All Chapter Notes, Concept and Important Formula 2. CONJUGATE COMPLEX : If \(z=a+i b\) then its conjugate complex is obtained by changing the sign of its imaginary part \(\&\) is denoted by \(\bar{z}\) . i.e. \(\bar{...

Indefinite Integration - Notes, Concept and All Important Formula

INDEFINITE INTEGRATION If  f & F are function of \(x\) such that \(F^{\prime}(x)\) \(=f(x)\) then the function \(F\) is called a PRIMITIVE OR ANTIDERIVATIVE OR INTEGRAL of \(\mathrm{f}(\mathrm{x})\) w.r.t. \(\mathrm{x}\) and is written symbolically as \(\displaystyle \int \mathrm{f}(\mathrm{x}) \mathrm{d} \mathrm{x}\) \(=\mathrm{F}(\mathrm{x})+\mathrm{c} \Leftrightarrow \dfrac{\mathrm{d}}{\mathrm{dx}}\{\mathrm{F}(\mathrm{x})+\mathrm{c}\}\) \(=\mathrm{f}(\mathrm{x})\) , where \(\mathrm{c}\) is called the constant of integration. Note : If \(\displaystyle \int f(x) d x\) \(=F(x)+c\) , then \(\displaystyle \int f(a x+b) d x\) \(=\dfrac{F(a x+b)}{a}+c, a \neq 0\) All Chapter Notes, Concept and Important Formula 1. STANDARD RESULTS : (i) \( \displaystyle \int(a x+b)^{n} d x\) \(=\dfrac{(a x+b)^{n+1}}{a(n+1)}+c ; n \neq-1\) (ii) \(\displaystyle \int \dfrac{d x}{a x+b}\) \(=\dfrac{1}{a} \ln|a x+b|+c\) (iii) \(\displaystyle \int e^{\mathrm{ax}+b} \mathrm{dx}\) \(=\dfrac{1}{...