Question

# The order of the differential equation of all tangent lines to the parabola y=x2 is

A
1
B
2
C
2
D
4

Solution

## The correct option is A 1The parametric form of the given equation is x=t,y=t2. The equation of any tangent at t is 2xt=y+t2, Differentiating we get 2t=y1(=dydx) putting this value in the above equation, we have  2xv12=y+(y12)2⇒4xy1=4y+y21 The order of this equation is 1 Hence (A) is the correct answer

Suggest corrections