Question
Solve the following differential equation :
$(\cot^{–1}y + x) dy = (1 + y^2) dx$

Answer

$\frac{\text{dx}}{\text{dy}}-\frac{\text{x}}{1+\text{y}^2}=\frac{\cot^{-1}}{1+\text{y}^{2}}$
$\text{I.F.}=\text{e}^{-\int\frac{\text{x}}{1+\text{y}^2}}=\text{e}^{\cot^{-1}\text{y}}$
$\text{x}.\text{e}^{\cot^{-1}\text{y}}=\int\frac{\cot^{-1}\text{y}\ \text{e}^{\cot^{-1}\text{y}}}{1+\text{y}^2}\text{dy}$
Integrating, we get
$\text{x}.\text{e}^{\cot^{-1}\text{y}}=\int\frac{\cot^{-1}\text{y}\ \text{e}^{\cot^{-1}\text{y}}}{1+\text{y}^2}\text{dy}$
put $\cot^{–1} y = t$
$=-\int\text{t }\text{e}^{\text{t}}\text{dt}$
$= (1 – t) e^t + c$
$\Rightarrow x = (1 – \cot^{–1}y) + ce^{–\cot–1 y}$

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 that $\int\limits_{0}^{\text{a}}\text{f(x)}\text{dx}=\int\limits_{0}^{\text{a}}\text{f}(\text{a}-\text{x})\text{dx},$ hence evaluate $\int\limits_{0}^\pi\frac{\text{x}\sin\text{x}}{1+\cos^2\text{x}}\text{dx}.$
Solve the follwing system of equations by matrix method:
$3x + 4y - 5 = 0$
$x - y + 3 = 0$
Let $\text{A}=\begin{bmatrix}1&-1&0\\2&1&3\\1&2&1\end{bmatrix}$ and $\text{B}=\begin{bmatrix}1&2&3\\2&1&3\\0&1&1\end{bmatrix},$ Find $A^T, B^T$​​​​​​​ and verify that.$(\text{A}\text{B})^\text{T}=\text{B}^\text{T}+\text{A}^\text{T}$
Differentiate w.r.t. x the function in Exercise:
$\text{x}^\text{x}+\text{x}^\text{a}+\text{a}^\text{x}+\text{a}^\text{a},$ for some fixed $a > 0$ and $x > 0$
If $\text{y}=(\sin\text{x}-\cos\text{x})^{\sin\text{x}-\cos\text{x}},\frac{\pi}{4}<\text{x}<\frac{3\pi}{4},$ find $\frac{\text{dy}}{\text{dx}}$
Solve the system of linear equation, using matrix method 2x + y + z = 1; $x - 2y - z = \frac{3}{2};\,\,3y - 5z = 9$
A shopkeeper has $3$ varieties of pens $'A', 'B'$ and $'C'$. Meenu purchased $1$ pen of each variety for a total of Rs $21$. Jeevan purchased $4$ pens of $'A'$ variety $3$ pens of $'B'$ variety and $2$ pens of $'C'$ variety for Rs $60$. While Shikha purchased $6$ pens of $'A'$ variety, $2$ pens of $'B'$ variety and $3$ pens of $'C'$ variety for Rs $70$. Using matrix method, find cost of each variety of pen.
Solve the following systems of linear equations by cramer's rule:
$x + y = 5,$
$y + z = 3,$
$x + z = 4$
How many sweaters of each type should the company make in a day to get a maximum profit? What is the maximum profit.
The equation of tangent at (2, 3) on the curve $y^{2} = \text{ax}^{3} + \text{b is y = 4x - 5}. $ Find the value of a and b.