... sau.Gia’su.’z1= a1+ ib1, z2= a2+ ib2. Khi d´o(I) Ph´ep cˆo.ng: z1± z2=(a1± a2) +i(b1± b2).(II) Ph´ep nhˆan: z1z2=(a 1a2 b1b2)+i(a1b2+ a2b1).(III) Ph´ep chia:z2z1=a 1a2+ b1b 2a21 + b21+ ia1b2− a2b 1a21 + b21·C´AC ... nhau(a1,b1)= (a2, b2) ⇐⇒a1= a2, b1= b2.(II) Ph´ep cˆo.ng1.1. D-i.nh ngh˜ıa sˆo´ph´u.c 7(a1,b1)+ (a2, b2)def=(a1+ a2, b1+ b2).1(III) Ph´ep nhˆan(a1,b1) (a2, b2)def=(a 1a2 b1b2,a1b2+ a2b1).Tˆa.pho..psˆo´ph´u.cdu.o..ck´yhiˆe.ul`aC. ... +1l`asˆo´thuˆa`na’o khi v`a chı’khi a2+ b2=1.Gia’i. Ta c´ow =(a − 1) + ib(a +1)+ib =a2+ b2− 1(a +1)2+ b2+ i2b(a +1)2+ b2·T`u.d´o suy r˘a`ng w thuˆa`na’o khi v`a chı’khia2+ b2− 1(a +1)2+ b2=0⇐⇒ a2+ b2=1. B`AI TˆA.PT´ınh1.(1...