5.0 Representation of complex number

5.1 Cartesian form (Geometric Representation)
5.2 Principal value of complex number
5.3 Properties of modulus
5.4 Trigonometric/Polar Representation

Complex number is represented as an ordered pair of real numbers i.e., $a+ib=(a,b)$. To each complex number there corresponds only one point in the plane and conversely to each point in the plane there corresponds only one complex number.