COMEDK2013MathematicsApplication of Derivatives
If tangent to the curve x=a t², y=2 a t is perpendicular to X -axis, then its point of contact is
Options
- A(a, a)
- B(0, a)
- C(0,0)
- D(a, 0)
Correct answer
C. (0,0)
Step-by-step solution
We have, x=a t², y=2 a t Now, d x d t =2 a t, d y d t =2 a d y d x = d y / d t d x / d t = 2 a 2 a t = 1 t Since, tangent is perpendicular to X -axis, then d y d x = 1 0 1 t = 1 0 t=0 x=a t²=0 and y=2 a t=0 So, required point is (0,0) .