Gradient of normal (1 Viewer)

[Getteral09]

hey ppl,I can't seem to get this maths problem, "Find the gradient of the normal to the parabola x^2 =4y at the point where x=2", to m=-1. Instead i keep getting m=1.So can any1 show me how to prove that the answer is right, not just a mistake?
Thanks,Getteral

 

[SoulSearcher]

y = x²/4
y' = x/2
x=2, y' = 1
therefore gradient of normal is -1 as -1*1 = -1

 

[Riviet]

I remember that the gradient of the normal is the negative reciprocal of the gradient of the tangent, ie gradient of normal = -1/(gradient of tangent)