Complex numbers are numbers of the form a + bi, where a and b are real numbers and i is defined as the imaginary unit and is equal to the principal square root of -1. High school students learn to perform arithmetic with complex numbers and to plot them in the complex plane. At advanced levels, students may also learn to represent complex numbers in terms of trigonometric functions and polar coordinates. Students will find this domain relevant to their previous studies of polynomials, as complex numbers provide solutions to polynomials with roots that cannot be found by considering only the real numbers. With knowledge of complex numbers, students can learn and apply the fundamental theorem of algebra, which states that a polynomial of degree n has exactly n complex roots counted with multiplicity.
Add, subtract, multiply and divide complex numbers.
Generalize knowledge of polynomials to include complex numbers.
Define and plot complex numbers using rectangular or polar coordinates.