Find the point on the curve `y^2=4x` which is nearest to the point (2, 1).

Explanation

`B(x_o,y_o)`

normal at B passes through A

`(y-y_o)=-1/(dy/dx)*(x-x_o)`

`(y-y_o)=-y_o/2(x-x_o)`
`1-y_o=-y_o +(x_oy_o)/2`

`x_oy_o=2`

`y_o^2=4x_o`

`x_oy_o*y_o^2=2*4x_o`

...