IV. TlfiN TRINH DAY HOC A OAT VAN OE
HCIGFNG DflN Bfll TflP SGK
Bai 1. Hudng ddn. Six dung true tiep cdng thiic : -—^ = —^—— + - ^ — - 7 / . c + di _ ac + bd ad-be .
a + bi~ a^+b^ a^+b^
cau a. Hudng ddn. Nhan ca tii va mdu vdi 3 + 2i
^, , 2 + i (2 + 0 ( 3 + 2 0 4 7 . Dapso. 3 - 2 j = j 3 = i 3 - ' l 3 ^ -
cau b. Hudng ddn. Nhan ca tii va mdu vdi 2 - v3i
^ , ,, 2 + V6 2V2-V3.
Dapso. H 1.
7 7
cau c. Hudng ddn. Nhan ca ttr va mdu vdi 2 + 3i
n- - 1 5 ^ 1 0 . Dapso. h — 1.
13 13
cau d. Hudng ddn. Nhan ca tur va mdu vdi - i
Ddp sd ^ ^ ^ = (5 - 2 0 ( - 0 = - 2 - U.
Bai 2. Hudng ddn. Sir dung tuih chdt ciia sd phiic nghich dao ciia z = a + bi la
a b . a ^ + b ^ a ^ + b ^
cau a. Hudng ddn. Tim sd phiic lien hgp cua z la 1 - 2i. Chia sd phiic lien hgp cho
a2 + b2
^ . . 1 l - 2 i 1 2 .
t > a p 5 0 . - — - 7 = = 1.
^ l + 2i 5 5 5
cau b. Hudng ddn. Tim so phiic lien hgp ciia z la 1 - 2i. Chia so phiic lien hgp cho
r , ' - 1 N/2+3i > ^ ^ 3
Dapso. —= = —-J - = + — 1.
V 2 - 3 i ( ^ ) 2 + ( - 3 ) 2 11 11
cau c. Huang ddn. Tim sd phiic lien hop cua z la 1- 2i. Chia sd phiic lien hgp cho
a + b
Dap so. ~ = —- = -I.
I 1
cau d. Hudng ddn. Lam tuang tu cac cau tren.
^, , 1 5-iV3 5 V3 .
Bai 3. Hudng ddn. Thuc hien cac phep nhan binh thudng. cau a. Ddp sd. - 2 8 + 4i.
OQ 1 ft
cau b. Dap sd. - — —i
5 5 cau a. Ddp 50. 32 + 13i _ ^ . ., 219 1 5 3 .
Cau a. Dap 5o. —— -— i
45 45
Bai 4. Hudng ddn. Thuc hien lien hgp cac phep toan vl sd phiic.
Caua.Tacd ( 3 - 2 i ) z = 7 + 3 i - 4 - 5 i = 3 - 2 i
Ddp sd. z = 1.
Cau b. Lam tuong tu cau a.
n- " 8 9 . Dapso. z = 1
5 5
cau c. Lam tuong tu cau a.
§4. Phurcfng t r i n h bac h a i v d i h e s o thi;fc ( t i e t 8 )