§76 Phasor relationships for r、 L and c Ra i R R 2 + jfu=√2cos(a+9)i=√2Icos(ar+g) 2V cos(at+9)=Rv2I cos(at +) ∠=RI∠q (9= U,i--in Phase RI§7-6 Phasor relationships for R、 L and C i + − R • I + − • V R  = Ri i f  = 2V cos(t +) i = 2I cos(t + ) 2V cos(t +) = R 2I cos(t +) ( ,i i n phase) V RI = − −  =       • • V = R I R：