Let \(A\) be a point on the \(x\)-axis. Common tangents are drawn from \(A\) to the curves \(x^2+y^2=8\) and \(y^2=16 x\…

Let \(A\) be a point on the \(x\)-axis. Common tangents are drawn from \(A\) to the curves \(x^2+y^2=8\) and \(y^2=16 x\). If one of these tangents touches the two curves at \(Q\) and \(R\), then \((Q R)^2\) is equal to