gaokao 2018 Q1

gaokao · China · national-I-science 5 marks Complex Numbers Arithmetic Modulus Computation

Let $z = \frac { 1 - \mathrm { i } } { 1 + \mathrm { i } } + 2 \mathrm { i }$, then $| z | =$
A. 0
B. $\frac { 1 } { 2 }$
C. 1
D. $\sqrt { 2 }$

Let $z = \frac { 1 - \mathrm { i } } { 1 + \mathrm { i } } + 2 \mathrm { i }$, then $| z | =$

A. 0

B. $\frac { 1 } { 2 }$

C. 1

D. $\sqrt { 2 }$