Find the point on the graph of f(x)=√x that is closest to the value (4,0).

Question

(differentiate the square of the distance from a point (x,√x) on the graph of f to the point (4,0).)

Answer 1

Square of distance from (4,0)
D(x)= ((x-4)^2+x)
For minimum, D'(x)=0
2(x-4)+1=0
x=7/2