- Phdn thuc va phdn ao cua sd phiic.
1. Giai cac phuang trinh sau
a) 2x2+3x + 7 = 0; b ) x ^ + 3 x + 7 = 0. 2. Tim hai sd phiic biet tong ciia chiing la 2 va tich ciia chiing la 7. 2. Tim hai sd phiic biet tong ciia chiing la 2 va tich ciia chiing la 7.
De2 Phdn 1. Trdc nghiem khdch quan (4 diem). Cdu 1. Hay diln diing, sai vao d trdng sau daỵ
(a) Sd phiic lien hgp ciia 3 + 2i la 3 - 2i [_] (b) Mđun cua so phiic 3 -2i la Vl3 |_| (c) Mđun ciia so phiic 3 + 2i la Vl3 |_| (d) Tich cua hai so phiic lien hgp la mdt so thuc |_|
Cdu 2. bdng l l + 2i , , 119 33 . _ 119 33 . (a) 1; (b) + 1; 125 125 125 125 , , 119 33 . ^^^ 119 33 . (c) 1 (d) + 1. 125 125 125 125
Cdu 3. Phuang trinh x^ - 2x + 3 = 0 cd tat cd cac nghiem la
(a)l + V2i; (b)l-V2i; (c) l + >;^i; 1-V2i ( d ) - l - V 2 i .
Cdu 4. il-i)il +4i) bdng
(a) 5 + 3 i ; (b) 5 - 3i; (c) 3 - 5i; (d) 3 + 5ị
Phdn 2. Tu ludn (6 diem)
1. Giai cac phuang trinh sau:
a)x^ + x ' - 2 = 0 ; b ) x ^ - x 2 + 2 = 0 2. Giai cac phuang trinh sau
a) (2- 3i)z + 2 = 5i; b ) ^ i z = 3 + ị
2 - 1
De3 Phdn Ị Trdc nghiem khdch quan (4 diem). Cdu 1. Hay diln diing, sai vao d trdng sau day :
(a) (1-20(1 + 20 = 5 D (b) (2-2i)(3 +20 = 10-21 D (c)(l-3i)(l + 30 = 10 D (d)(l-4i)(l + 40 = 15. D
Cdu 2. Hay diln diing, sai vao d trdng sau day :
( c ) | ^ = ^ D ( d ) ^ ^ = ^ ^ D ( d ) ^ ^ = ^ ^ D
3 + i 10
Cdu 3. Trong cac phuang trinh sau phuang trinh nao khdng cd nghiem thuc:
(a) x2-3x + l = 0; (b) x^-3x + l = 0 ; (c) x^+3x + 7 = 0 ; ( d ) x 2 - 3 x - l = 0
Cdu 4. Trong cac phuang trinh sau phuong trinh nao khdng cd nghiem phurc:
(a) x 2 - 3 x + l = 0 ; (b) x ^ - 3 x + l = 0 ; ( c ) x 2 + 3 x + 7 = 0 ; ( d ) x 2 - 3 x - l = 0
Phdn 2. Tu ludn (6 diem)
1. Giai cac phuang trinh sau
a ) x 3 - l ; b) x'*-x^ + 2 x - l = 0. 2. Tim mđun ciia cdc sd phiic sau :
a ) 3 + 21i; b) 33 + 21ị
Di4 Phdfi 1. Trdc nghiem khdch quan (4 diem). Cdu 1. Hay diln diing, sai vao d trdng sau daỵ
(a) Tap hgp cac sd phiic cd mđun bdng 1 la mdt dudng trdn [ ] (b) Tap hgp cac sd phiic cd mđun < 1 la mdt hinh trdn [ ]
(c) Phuang trinh x^ - 1 = 0 cd mdt nghiem [ ] (d) Phuang trinh x^ - 1 = 0 cd mdt nghiem thuc [ ]
^. , 10 + 2i . - ,u^ 22 6 . ( b ) - + - i ; ( d ) - ^ - ^ i . 5 5 (b) 1 - 12i; (d) 1 + 12ị (a) (c) Cdu 3. (a) (c) 3 + i 22 6 . 1; 5 5 22 6 . + - 1 5 5 12 + i ' , bang i 1 2 - i 1 - l - 1 2 i
Cdu 4. (1 +i)^bdng
(a) - 2 + 2i; (c) 1 + 2i
fihdn 2. Tu ludn (6 diem)