d = v Δ t d=v\Delta t d=vΔt c τ = c Δ t + v Δ t c\tau=c\Delta t+v\Delta t cτ=cΔt+vΔt c τ ′ = c Δ t − v Δ t c\tau'=c\Delta t-v\Delta t cτ′=cΔt−vΔt c τ ′ c τ = c Δ t − v Δ t c Δ t + v Δ t \frac{c\tau'}{c\tau}=\frac{c\Delta t-v\Delta t}{c\Delta t+v\Delta t} cτcτ′​=cΔt+vΔtcΔt−vΔt​ τ ′ = c − v c + v τ \tau'=\frac{c-v}{c+v}\tau τ′=c+vc−v​τ

d = v Δ t d=v\Delta t d=vΔt c f r − d = c Δ t \frac{c}{f_r}-d=c\Delta t fr​c​−d=cΔt Δ t = 1 c + v c f r \Delta t=\frac{1}{c+v}\frac{c}{f_r} Δt=c+v1​fr​c​ d = 1 f r c v c + v d = \frac{1}{f_r}\frac{cv}{c+v} d=fr​1​c+vcv​ c f r ′ = c Δ t − v Δ t \frac{c}{f_r'}=c\Delta t-v\Delta t fr′​c​=cΔt−vΔt f r ′ = c + v c − v f r f_r'=\frac{c+v}{c-v}f_r fr′​=c−vc+v​fr​ f 0 ′ = c + v c − v f 0 f_0'=\frac{c+v}{c-v}f_0 f0′​=c−vc+v​f0​ f d = f 0 ′ − f 0 = c + v c − v f 0 − f 0 f_d=f_0'-f_0=\frac{c+v}{c-v}f_0-f_0 fd​=f0′​−f0​=c−vc+v​f0​−f0​ v < < c v