UPSC NDA II 2015 Mathematics Solved Paper

The eq. of parabolas having vertex at (0,0) & focus at (a, 0), where (a >0) is:
y2=4ax.....(1)
2y.

dy

dx

=4a  [on differentiating]
On putting the value of (4a) in eq. (1) we get.
2x⋅‌‌

dy

dx

−y=0
in order =1 & degree = 1.