. 1 2. . 4.2 . , .
: P=P1+P2=UABiA+UCBiB. iA=iAB-iCA; ic=iCA-iBC, UCB UBC, .. , : P=P1+P2=UABiAB+ UBCiBC+ UCAiCA=PAB+PBC+PCA (PAB, PBC, PCA , ). .. W ( UAB=UBC=UCA=U; IAB=IBC=ICA=I; IA=IB=IC=I; jAB=jBC=jCA=j), , :
P1=UABIAcos(UAB^IA)= UIcos(UAB^IA);
P1=UBICcos(UCB^IC)= UIcos(UCB^IC)
: (UAB^IA)=300+j; (UCB^IC)=30-j (j - ). 1+2, 1+2= UIcosj.
j=00 ;
j=600 0
j>600 .
( )
.
. , .. P=UAIAcosjA+ UAIBcosjB+ UAICcosjC
( )
, , .
Pw=UBCIAcos(900-j)=UBCIAsinj
.. (Q=3Q=3UIsinj= UIsinj), , Pw= UIsinj=Q.
( )
PW1+PW2=UBCIAcos(UBC^IA)+UABICcos(UAB^IC)=UBCIAcos(900-j)+UBCICcos(900-j). , PW1+PW2 =2UIsinj. /2,