IB DP Maths: AI HL复习笔记1.5.2 Modulus & Argument

How do I find the modulus of a complex number?

What features should I know about the modulus of a complex number?

How do I find the argument of a complex number?

• The argument of a complex number is the angle that it makes on an Argand diagram
  • The angle must be taken from the positive real axis
  • The angle must be in a counter-clockwise direction
• Arguments can be calculated using right-angled trigonometry
  • This involves using the tan ratio plus a sketch to decide whether it is positive/negative and acute/obtuse

What features should I know about the argument of a complex number?

What are the rules for moduli and arguments under multiplication and division?