Question
Form the differential equation of all the circle which pass through the origin and whose centres lies in x-axis.

Answer

The equation of the family of circles that pass through the origin (0, 0) and whose centres lie on the x-axis is given by

$(\text{x}-\text{a})^2+\text{y}^2=\text{a}^2\ ...(1)$

where a are arbitrary constants.

As this equation has only one arbitrary constant, we shall get a first order differential equation.

Differentiating (1) with respect to x, we get

$2(\text{x}-\text{a})+2\text{y}\frac{\text{dy}}{\text{dx}}=0$

$\Rightarrow\text{x}-\text{a}+\text{y}\frac{\text{dy}}{\text{dx}}=0$

$\Rightarrow\text{x}+\text{y}\frac{\text{dy}}{\text{dx}}=\text{a}$

Substituting the value of a in equation (2), we get

$\Big(\text{x}-\text{x}-\text{y}​​\frac{\text{dy}}{\text{dx}}\Big)^2+\text{y}^2=\Big(\text{x}+\text{y}​​\frac{\text{dy}}{\text{dx}}\Big)^2$

$\Rightarrow\text{y}^2\Big(​​\frac{\text{dy}}{\text{dx}}\Big)^2+\text{y}^2=\text{x}^2+2\text{xy}​​\frac{\text{dy}}{\text{dx}}+\text{y}^2\Big(​​\frac{\text{dy}}{\text{dx}}\Big)^2$

$\Rightarrow2\text{xy}​​\frac{\text{dy}}{\text{dx}}+\text{x}^2=\text{y}^2$

It is the required differential equation.

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

Find gof and fog when $f: R \rightarrow R$ and $g: R \rightarrow R$ are defined by: $f(x)=2 x+3$ and $g(x)=x^2+5$
Solve the following initial value problems:
$\text{x}\frac{\text{dy}}{\text{dx}}+\text{y}=\text{x}\cos\text{x}+\sin\text{x},\text{ y}\Big(\frac{\pi}{2}\Big)=1$
If $\Big(\sin^{-1}\text{x}\Big)^2+\Big(\cos^{-1}\text{x}\Big)^2=\frac{175\pi^2}{36},$ find x.
Evaluate the following integrals:$\int_{0}^\limits{\frac{\pi}{2}}\frac{1}{\text{a}^2\sin^2\text{x}+\text{b}^2\cos^2\text{x}}\text{ dx}$
Extend the definition of the following by continuity $\text{f(x)}=\frac{1-\cos7(\text{x}-\pi)}{5(\text{x}-\pi)^2}$ at the point $\text{x}=\pi.$
Solve the following differential equation
$\frac{\text{dy}}{\text{dx}}=\frac{\text{x e }^\text{x}\log\text{x}+\text{e}^\text{x}}{\text{x}\cos\text{y}}$
Show that the equation of the curve whose slope at any point is equal to y + 2x and which passes through the origin is $\text{y}+2(\text{x}+1)=2\text{e}^{2\text{x}}.$
A publisher sells a hard cover edition of a text book for Rs. 72.00 and paperback edition of the same ext for Rs. 40.00. Costs to the publisher are Rs. 56.00 and Rs. 28.00 per book respectively in addition to weekly costs of Rs. 9600.00. Both types require 5 minutes of printing time, although hardcover requires 10 minutes binding time and the paperback requires only 2 minutes. Both the printing and binding operations have 4,800 minutes available each week. How many of each type of book should be produced in order to maximize profit?
Differentiate the following functions with respect to x:
$\sin\Big(\frac{1+\text{x}^2}{1-\text{x}^2}\Big)$
If $f : R \rightarrow R$ be defined by $f(x) = x^3 - 3$, then prove that $f^{-1}$ exists and find a formula for $f^{-1}$. Hence, find $f^{-1}(24)$ and $f^{-1}(5)$.