Tính các lũy thừa sau: a) (3 – 4i)^2;
Giải thích
a) (3-4i)2 = 32 − 2.3.4i + (4i)2 = −7 − 24i
b) (2+3i)3 = 23 + 3.22.3i + 3.2.(3i)2 + (3i)3 = −46 + 9i
c) [(4 + 5i) – (4 +3i)]5 = (2i)5 = 32i
d) (2-i3)2 = −1 − 2i6
a) (3-4i)2 = 32 − 2.3.4i + (4i)2 = −7 − 24i
b) (2+3i)3 = 23 + 3.22.3i + 3.2.(3i)2 + (3i)3 = −46 + 9i
c) [(4 + 5i) – (4 +3i)]5 = (2i)5 = 32i
d) (2-i3)2 = −1 − 2i6