MATHS differentialtion

y=(1/4)x^2 ; dy/dx=x/2. Let the point on the parabola which is closest to the point (0,5) is (h,k). Then the line joining (0,5) and (h,k) should be normal to the tangent line about (h,k). So [(k-5)/h][h/2]=-1 =>k=3 Then h=2√ 3 or
-2√ 3

So, the required points are (-2√ 3, 3) and (2√ 3,3)

2010-12-29 22:29:19 補充：
YES