From the differential equation of the family of circles having centre on y-axis and radius 3 units.
Let the centre of the circle on y-axis be(0,b).
The differential equation of the family of circles with centre at (0,b)and radius 3 is as
follows:
x2+(y-b)2=32
\(\Rightarrow \) x2+(y-b)2=9 ...(1)
Differentiating equation(1) with respect to x, we get:
2x+2(y-b).y'=0
\(\Rightarrow\) (y-b).y'=-x
\(\Rightarrow\) y-b=-\(\frac{x}{y'}\)
Substituting the value of (y-b)in equation(1),we get:
\(x^2+(-\frac{x}{y'})^2=9\)
\(\Rightarrow x^2[1+\frac{1}{(y')^2}]=9\)
\(\Rightarrow\) x2((y')2+1)=9(y')2
\(\Rightarrow\) (x2-9)(y')2+x2=0
This is the required differential equation.
What is the Planning Process?
A relation between involved variables, which satisfy the given differential equation is called its solution. The solution which contains as many arbitrary constants as the order of the differential equation is called the general solution and the solution free from arbitrary constants is called particular solution.
Read More: Formation of a Differential Equation