Tangents PA and PB are drawn to the circle `x^(2)+y^(2)=4` from an external point P lying on the Time y = x such that the angle `theta` between the tangents satisfies `(pi)/(3) le theta le (2pi)/(3)`. The co - ordinates of the point P, if the perimeter of `DeltaPAB` is maximum for all `theta` are
{}