(∫_0^∞)P(v) dv=1Or,K(∫_0^∞)(e^(-((((v-(Subscript[v, 0])))^2)/(2(σ^2))))) dv=1Let   v'=(((v-(Subscript[v, 0])))/((Sqrt[2])σ))\[Implies]dv'=(dv/((Sqrt[2])σ))Or,K(∫_0^∞)(e^(-(((v'))^2))) dv'=1Or,K·σ·(Sqrt[(π/2)])((erfc(-((Subscript[v, 0])/((Sqrt[2])σ))))^(-((Subscript[v, 0])/((Sqrt[2])σ))))=1Or,K=(1/(σ(Sqrt[(π/2)])erfc(-((Subscript[v, 0])/((Sqrt[2])σ)))))