第4章 4.3

(1)

4i(32i)=3+6i4i - (3 - 2i) = -3 + 6i

(2)

1+5i2(4i)=9+7i1 + 5i - 2(-4 - i) = 9 + 7i

(3)

2(53i)3(32i)=106i9+6i=12(5 - 3i) - 3(3 - 2i) = 10 - 6i - 9 + 6i = 1

(4)

(43i)(2+i)=82i+3=112i(4 - 3i)(2 + i) = 8 - 2i + 3 = 11 - 2i

(5)

(1+i)2=1+2i1=2i(1 + i)^2 = 1 + 2i - 1 = 2i

(6)

(2i)(3+2i)=32i+2=42i(\sqrt{2} - i)(3 + \sqrt{2}i) = 3\sqrt{2} - i + \sqrt{2} = 4\sqrt{2} - i

(7)

2i=2i\frac{2}{i} = -2i

(8)

6+4i5i=(6+4i)(5+i)(5i)(5+i)=30+26i425+1=26+26i26=1+i\frac{6 + 4i}{5 - i} = \frac{(6 + 4i)(5 + i)}{(5 - i)(5 + i)} = \frac{30 + 26i - 4}{25 + 1} = \frac{26 + 26i}{26} = 1 + i

解説: r31bn1z