3 =√9.332+11.16 √9332+1162 cos ot 16 Sin at √9.332+11.16 146cos50° cos at-Sin50°Smo] 146cos(o+509)…( 方法二运用矢量运算 i→in(O4矢量) Y B i2→i2(OB矢量) →n(OC矢量) 根据矢量图 50° Im A 14.6 0|60°30 q3=50° 于是i3=14.6CoS(o1+50°)
2 2 = 9.33 +11.16 2 2 9.33 11.16 9.33 + t Sint 2 2 9.3 3 1 1.1 6 1 1.1 6 cos + − ( t ) (A) t Sin Sin t 14.6cos 50 ........ 14.6 cos50 cos 50 = + = − 方法二:运用矢量运算 Y 0 X B C 60 30 50 A m I 2 m I1 m I3 ( ) ( ) ( ) i 14.6CoS( 50 ) 50 14.6 3 3 3 3 3 2 2 1 1 = + = = → → → t I i I OC i I OB i I OA m m m m 于是 根据矢量图 矢量 矢量 矢量 10 5
方法三运用复数运算 11.16 e30 5 50° 10e 60 复平面933 2 3m 2 5(cos30°+jSm30°)+10(cos60°+jSim60°) (5cos30°+10cos60°)+/(5Sm30°+10Sim60° =933+j11.16 14.6e15° 于是2=146c0s(o+50°)
50 11.16 +j 9.33 m I3 方法三.运用复数运算: = 60 2 10 j I m e = j30 I1m 5e ( ) ( ) ( ) ( ) = ( + ) = = + = + + + = + + + = + 14.6cos 50 14.6 9.33 11.16 5cos30 10cos60 5 30 10 60 5 cos30 30 10 cos60 60 3 5 0 3 1 2 i t e j j Sin Sin jSin jSin I I I j m m m 于是 复平面