Lesson: The Argument of a Complex Number Mathematics • Third Year of Secondary School

Students will be able to

• understand that the argument of a complex number, , is the angle that the line from the origin to makes with the positive real axis,
• understand that the argument of a complex number is measured in a counterclockwise direction,
• understand that the principle argument is usually given in radians in the range ,
• find the argument of a complex number in any of the 4 quadrants using formulas involving arctan,
• understand how to use the properties of the argument of a complex number (or its conjugate) to solve problems.