The number of arbitrary constants in the particular solution of a differential equation
of third order are:
(A) 3
(B) 2
(C) 1
(D) 0
9 4  Formation of a Differential Equation whose General Solution is given
We know that the equation
x2 + y2 + 2x – 4y + 4 = 0 (1)
represents a circle having centre at (–1, 2) and radius 1 unit © NCERT
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MATHEMATICS
386
Differentiating equation (1) with respect to x, we get
dy
dx  =
1
2
x
y
−+
 (y ≠ 2)