Unit 5 - Objective 1 - Basic Definitions of Complex Numbers Quick Review Imaginary numbers allow us to represent the square root of a negative number or the product of a real number and the imaginary unit, j. The square root of a negative number is called a pure imaginary number. The symbol represents the principal square root of a and is never negative. If a is a real number, then is a pure imaginary number and where Example 1 Note: since Rectangular form of a complex number The form a+bj is known as the rectangular form of a complex number, where a is the real part and b is the imaginary part. Two complex numbers are equal if both the real parts are equal and the imaginary parts are equal. Given a+bj and c+dj are two complex numbers. Then, a+bj = c+dj if and only if a=c and b=d. Example 2 Solve 4+3j = (x+2) + 7j + yj Real parts are equal 4=x+2 2=x Imaginary parts are equal 3j=7j+yj 3=7+y -4=y Unit Outline // Course Outline // Home Page Copyright © 1996 by B. Chambers and P. Lowry. All Rights Reserved.