记住:要把分母部分的复数实数化,只需分子分母同乘分母的共轭就行了.
1).B
i÷(1+i)+(1+√3i)(1+√3i)=
[i*(1-i)]/[(1+i)(1-i)]+(1+√3i)(1+√3i)=
(1+i)/2-2+2√3i
实部小于0,虚部大于0,在2象限.
2).C
(a+3i)÷(1+2i)=
[(a+3i)(1-2i)]÷[(1+2i)(1-2i)]
分母是实数,只需考虑分子部分.
(a+3i)(1-2i)=a+6+3i-2ai
纯虚数要求:实部=0,则
a+6=0
a=-6
C