A curve has parametric equations :

$\displaystyle x=t^3-\mu t$ , where $\displaystyle \mu$ is a constant

$\displaystyle y=\frac{t^2}{1+t^2}$

(1) Show that the curve is symmetrical about the y-axis

(2) For $\displaystyle \mu>0$ ,find in terms of $\displaystyle \mu$ the coordinates of the point where the curve intersects itself.