Find the equation of normal to the parabola
y2=16x at point (4,8)
x + y - 4 = 0
For a given point (h,k) on the parabola y2=4ax the equation of normal at that point is
y−k=−k2a(x−h)
Here (h,k) = (4,8) and a = 4.
Therefore equation of normal is
y−8=−82(4)(x−4)
x+y−4=0