I figured out the equation of normal by using equation of line and it is
$$y=-\frac{dx}{dy}(x-1)$$
Using this I found the equation of curve which is
$$`y^{2}+x^{2}-2x=0$$
Then for common tangent I equated the $$\frac{dy}{dx}$$ of parabola and curve and I'm getting $x=1/3$
But the answer I have says tangent is $x=0$ What am I doing wrong?
I am not sure how you got $x = 1/3$. From the graphs of the curves, it is clear that the common tangent is $x=0$