Question
Evaluate the follwing intregals:
$\int\frac{\text{x}^2}{(\text{x}-1)(\text{x}^2+1)}\ \text{dx}$

Answer

$\text{I}=\int\frac{\text{x}^2}{(\text{x}-1)(\text{x}^2+1)}\ \text{dx}$
$\frac{\text{x}^2}{(\text{x}-1)^2(\text{x}^2+1)}=\frac{\text{A}}{(\text{x}-1)}+\frac{\text{Bx}+\text{C}}{\text{x}^2+1}$
$=\frac{\text{A}(\text{x}^2+1)+(\text{Bx}+\text{C})(\text{x}-1)}{(\text{x}-1)(\text{x}^2+1)}$
$\Rightarrow\frac{\text{x}^2}{(\text{x}+1)(\text{x}^2+1)}=\frac{(\text{A}+\text{B})\text{x}^2+(\text{C}-\text{B})\text{x}+(\text{A}-\text{C})}{(\text{x}-1)(\text{x}^2+1)}$
Comapairing coefficient, we get
$\text{A}+\text{B}=\text{C}=\frac{1}{2}$
$\therefore\text{I}=\frac{1}{2}\int\frac{1}{(\text{x}-1)\ \text{dx}}+\frac{1}{2}\int\frac{\text{x}}{\text{x}^2+1}\ \text{dx}+\frac{1}{2}\int\frac{1}{\text{x}^2+1}\ \text{dx}$
$=\frac{1}{2}\ln|\text{x}-1|+\frac{1}{4}\ln|\text{x}^2+1|+\frac{1}{2}\tan^{-1}\text{(x)}+\text{C}$

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

If $\text{x}-\text{e}^{\frac{\text{x}}{\text{y}}},$ prove that $\frac{\text{dy}}{\text{dx}}=\frac{\text{x}-\text{y}}{\text{x}\log\text{x}}$
Let S be the set of all real numbers except -1 and let '*' be an operation defined by a * b = a + b + ab for all a, b ∈ S. Determine whether '*' is a binary operation on S. If yes, check its commutativity and associativity. Also, solve the equation (2 * x) * 3 = 7.
Differentiate the following functions from first principles:
$\sin^{-1}(2\text{x}+3)$
Find the vector equation of a line which is parallel to the vector $2\hat{\text{i}}-\hat{\text{j}}+3\hat{\text{k}}$ and which passes through the point (5, -2, 4). Also, reduce it to cartesian from.
Solve the following differential equation:
$(\text{x}+\text{y})^2\frac{\text{dy}}{\text{dx}} = 1$
Evaluate the following integrals:
$\int_{0}^\limits{\frac{\pi}{2}}\frac{\text{x}+\sin\text{x}}{1+\cos\text{x}}\text{ dx}$
Find a particular solution of the differential equation $\frac{ dy }{ dx }+2 y \cot x=4 x \operatorname{cosec} x$ $(x \neq 0)$, given that $y=0$, when $x=\frac{\pi}{2}$.
Solve the following differential equation
$\text{C}(\text{x})=2+0.15\text{x},\text{C}(0)=100$
Evaluate the follwing intregals:
$\int\frac{1}{\text{x}(\text{x}^4-1)}\ \text{dx}$
Find the vector equation of the plane passing through points $3\hat{\text{i}}+4\hat{\text{j}}+2\hat{\text{k}},2\hat{\text{i}}-2\hat{\text{j}}-\hat{\text{k}}$ and $7\hat{\text{i}}+6\hat{\text{k}}.$