Question
Integrate the function in Exercise:
$\frac{1}{\text{x}-\text{x}^{3}}$

Answer

$\frac{1}{\text{x}-\text{x}^{3}}=\frac{1}{\text{x}(1-\text{x}^{2})}=\frac{1}{\text{x}(1-\text{x})(1+\text{x})}$ $\text{Let}\frac{1}{\text{x}(1-\text{x})(1+\text{x)}}=\frac{\text{A}}{\text{x}}+\frac{\text{B}}{(1-\text{x})}+\frac{\text{C}}{1+\text{x}}$ $\Rightarrow1=\text{A}(1-\text{x}^{2})+\text{B}\text{x}(1+\text{x})+\text{c}\text{x}(1-\text{x})$$\Rightarrow1=\text{A}-\text{A}\text{x}^{2}+\text{B}\text{x}+\text{B}\text{x}^{2}+\text{C}\text{x}-\text{C}\text{x}^{2}$
Equating the coefflclents of $\text{x}^{2},\text{x}$ and constant term, we obtain $-\text{A}+\text{B}-\text{C}=0$ $\text{B}+\text{C}=0$ $\text{A}=1$ on solving these equations, we obtain$\text{A}=1,\text{B}=\frac{1}{2},\text{and}\ \text{C}=\frac{1}{2}$
from eqution (1), we obtain $\frac{1}{\text{x}(1-\text{x})(1+\text{x})}=\frac{1}{\text{x}}+\frac{1}{2(1-\text{x})}-\frac{1}{2(1+\text{x})}$ $\Rightarrow\int\frac{1}{\text{x}(1-\text{x})(1+\text{x}}\text{dx}=\int\frac{1}{\text{x}}\text{dx}+\frac{1}{2}\int\frac{1}{1-\text{x}}\text{dx}-\frac{1}{2}\int\frac{1}{1+\text{x}}\text{dx}$ $=\log|\text{x}|-\frac{1}{2}\log|(1-\text{x})|-\frac{1}{2}\log|(1+\text{x)}|$ $=\log|\text{x}|-\log\bigg|(1-\text{x})^{\frac{1}{2}}\bigg|-\log|(1+\text{x)}^{\frac{1}{2}}\bigg|$ $=\log\left|\frac{\text{x}}{(1-\text{x)}^{\frac{1}{2}}(1+\text{x)}^{\frac{1}{2}}}\right|+\text{C}$ $=\log\left|\bigg(\frac{\text{x}^{2}}{1-\text{x}^{2}}\bigg)^{\frac{1}{2}}\right|+\text{C}$ $=\frac{1}{2}\log\left|\frac{\text{x}^{2}}{1-\text{x}}\right|+\text{C}$

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 function $f: R \rightarrow R , f(x)=x^2+2$ and $g: R \rightarrow R$ $g(x)=\frac{x}{x-1}, x \neq 1$ then find $f o g$ and $g o f$ and also find $( fog )(2)$ and $( gof )(-3)$ ?
If $\sqrt{1-\text{x}^2}+\sqrt{1-\text{y}^2}=\text{a}(\text{x}-\text{y}),$ prove that $\frac{\text{dy}}{\text{dx}}=\frac{\sqrt{1-\text{y}^2}}{1-\text{x}^2}$
Show that area of the parallelogram whose diagonals ate given by $\vec{\text{a}}$ and $\vec{\text{b}}$ is $\frac{|\vec{\text{a}}\times\vec{\text{b}}|}{2}.$ Also, find the area of the parallelogram, whose diagonals are $2\hat{\text{i}}-\hat{\text{j}}+\hat{\text{k}}$ and $\hat{\text{i}}+3\hat{\text{j}}-\hat{\text{k}}.$
Using the method of interation, find the area of the region bounded by the following lines:
3x - y - 3 = 0, 2x + y - 12 = 0, x - 2y - 1 = 0.
The function $y = a$ log $x + bx^2 + x$ has extreme values at $x = 1$ and $x = 2$. Find a and b.
Solve the following systems of linear equations by cramer's rule:
2x - 3z + w = 1,
x - y + 2w = 1,
-3y + z + w = 1,
x + y + z = 1
Evaluate the following integrals:
$\int\limits^{\frac{\pi}{3}}_{\frac{\pi}{6}}\frac{\sqrt{\tan\text{x}}}{\sqrt{\tan\text{x}}+\sqrt{\cot\text{x}}}\text{ dx}$
Using differentials, find the approximate values of the following:
$\frac{1}{(2.002)^2}$
Evaluate the following integrals as limit of sum:
$\int\limits^2_{0}\text{e}^{\text{x}}\text{ dx}$
Two schools $A$ and $B$ want to award their selected students on the values of sincerity, truthfulness and helpfulness. The school A wants to award $₹ x$ each, $₹ y$ each and $₹ z$ each for the three respective values to $3, 2$ and $1$ students respectively with a total award money of $₹ 1,600$. School $B$ wants to spend $₹ 2,300$ to award its $4, 1$ and 3 students on the respective values (by giving the same award money to the three values as before). If the total amount of award for one prize on each value is $₹ 900$, using matrices, find the award money for each value. Apart from these three values, suggest one more value which should be considered for award.