(1)
represents a circle having centre at (–1, 2) and radius 1 unit © NCERT
not to be republished
MATHEMATICS
386
Differentiating equation (1) with respect to x, we get
dy
dx  =
1
2
x
y
−+
 (y ≠ 2) (2)
which is a differential equation You will find later on [See (example 9 section 9