-A/2=Acos(@t+2) →0t+p2=±2π/3 0t+02=-2π/3 △0=(0t+0)-(0t+p2) --(2)-元 ωt +→ ϕ2 = ± 2π 3 =− ωtAA +ϕ2 )cos(2 ωt +ϕ2 = − 2π 3 )()( Δϕ = ω +ϕ1 − ω +ϕ2 tt ) 32π ( 3π −−= = π x 3 π π 3 2 −