Question
Evaluate the following definite integrals:$\int_{1}^\limits{3}\frac{\log\text{x}}{(\text{x}+1)^2}\text{ dx}$

Answer

Let $\text{I}=\int_{1}^\limits{3}\frac{\log\text{x}}{(\text{x}+1)^2}\text{ dx}$ Then,$\text{I}=\Big[\frac{-1}{1+\text{x}}\log\text{x}\Big]^3_1-\int_{1}^\limits{3}\Big(\frac{1}{\text{x}+1}\Big)\text{dx}$
$\Rightarrow\text{I}=\Big[\frac{-1}{1+\text{x}}\log\text{x}\Big]^3_1+\int_{1}^\limits{3}\frac{1}{\text{x}(\text{x}+1)}\text{ dx}$
$\Rightarrow\text{I}=\Big[\frac{-1}{1+\text{x}}\log\text{x}\Big]^3_1+\int_{1}^\limits{3}\Big(\frac{1}{\text{x}}-\frac{1}{\text{x}+1}\Big)\text{dx}$
$\Rightarrow\text{I}=\Big[\frac{-1}{1+\text{x}}\log\text{x}\Big]^3_1+\big[\log\text{x}-\log(\text{x}+1)\big]^3_1$
$\Rightarrow\text{I}=\frac{-1}{4}\log3+\log3-\log4+\log2$
$\Rightarrow\text{I}=\frac{3}{4}\log3-\log2$

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

Prove the following results:
$\sin^{-1}\frac{4}{5}+2\tan^{-1}\frac{1}{3}=\frac{\pi}{2}$
If the origin is the centroid of the triangle whose vertices are $A (2, p,-3), B (q,-2,5)$ and $R (-5,1, r)$, then find the values of $p, q, r$.
Using truth table prove that : $p \leftrightarrow q=(p \wedge q) \vee(\sim p \wedge \sim q)$
If $\vec{\text{a}}=2\hat{\text{i}}-\hat{\text{j}}+\hat{\text{k}},\vec{\text{b}}=\hat{\text{i}}+\hat{\text{j}}-2\hat{\text{k}}$ and $\vec{\text{c}}=\hat{\text{i}}+3\hat{\text{j}}-\hat{\text{k}}.$ find $\lambda$ such that $\vec{\text{a}}$ is perpendicular to $\lambda\vec{\text{b}}+\vec{\text{c}}.$
Evaluate the following definite integrals:$\int_{2}^\limits{3}\frac{\text{x}}{\text{x}^2+1} \text{ dx}$
Find the inverse of $A=\left[\begin{array}{lll}3 & 2 & 6 \\ 1 & 1 & 2 \\ 2 & 2 & 5\end{array}\right]$ by using elementary row transformations.
Solve the following differential equations : $x \sin \frac{d y}{d x}+(x \cos x+\sin y)=\sin x$
A, B, and C are independent witness of an event which is known to have occurred. A speaks the truth three times out of four, B four times out of five and C five times out of six. What is the probability that the occurrence will be reported truthfully by majority of three witnesses?
Find in vector form as wel as in cartesian form, the equation of the line passing through the points $A(1, 2, -1)$ and $B(2, 1, 1)$.
Prove that: $\int_0^{ a } f (x) d x=\int_0^{ a } f ( a -x) d x$. Hence find $\int_0^{\frac{\pi}{2}} \sin ^2 x d x$