Basic Relations for Rock Physics

Poisson's Ratio (ν) and ((Subscript[V, P])/(Subscript[V, S]))

clear all
VpVs=(Sqrt[((2(1-#))/((1-2#)))])&

Manipulate[ Plot[
			VpVs[ν],{ν,-2,2},
			PlotRange->{-5,10},
			AxesLabel->{Poisson,(Vp/Vs)},
			Filling->{1->1},Epilog->{PointSize@0.02,Point@{ν,VpVs[ν]}}
		],{ν,-2,2}]