Show that the curve for which the normal at every point passes through a fixed point is a circle.

Explanation

Let fixed point be `(h, k)`

`y=f(x)`

`frac{dy}{dx}=M_T`

`M_T|_(p(x, y))=frac{dy}{dx}`

`=frac{-dx}{dy}`

Equantion of `N` at `P(x, y)`

`Y-y=-frac{dx}{dy}(X-x)`

`k-y=frac{-dx}{dy}(h-x)`
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