gaokao 2017 Q3

gaokao · China · national-I-arts 5 marks Complex Numbers Arithmetic Complex Division/Multiplication Simplification

Among the following expressions, which has a result that is a pure imaginary number?
A. $i(1 + i)^2$
B. $i^2(1 - i)$
C. $(1 + i)^2$
D. $i(1 + i)$

Among the following expressions, which has a result that is a pure imaginary number?

A. $i(1 + i)^2$

B. $i^2(1 - i)$

C. $(1 + i)^2$

D. $i(1 + i)$