VITEEE 2018 Paper

s x3−3xy2 + 2 = 0
differentiating w.r.t. x:
3x2 - 3x (2y)

dy

dx

- 3y2 = 0
⇒

dy

dx

=

3x2−3y2

6xy

and 3x2y−y3−2 = 0
differentiating w.r.t. x
⇒ 3x2

dy

dx

+ 6xy - 3y2

dy

dx

= 0
⇒

dy

dx

= - (

6xy

3x2−3y2

)
Now, product of slope
=

3x2−3y2

6xy

× - (

6xy

3x2−3y2

) = - 1
∴ they are perpendicular.
Hence, angle = π/2