The normal to the curve x2 = 4y passing (1,2) is
It is given that the equation of curve is x2 = 4y
Differentiating w.r.t. x, we get,
The slope of the normal to the given curve at point (h,k) is
Then, the equation of the normal to the curve at (h,k) is
⇒ y – k =
Now, it is given that the normal passes through the point (1,2)
Thus, we get,
⇒ 2 – k =
⇒ k = ………………(1)
Since (h,k) lies on the curve x2 = 4y, we have h2 = 4k
⇒ k =
Now putting the value of of k in (1), we get
⇒ h3 = 8
⇒ h = 2
Therefore, the equation of the normal is given as:
⇒ y – 1 =
⇒ y - 1 = - (x - 2)
⇒ x + y = 3