Argument  -  The angle created by the positive real axis and the segment connecting the origin to the plot of a complex number in the complex plane.

Complex Conjugate  -  The complex conjugate of a given complex number a + bı is a - bı.

Complex Number  -  The set of all numbers of the form a + bı, where a and b are real numbers. The real numbers are all complex numbers.

Complex Plane  -  A plane with two perpendicular axes, the real axis and the imaginary axis, on which a complex number a + bı is plotted at the coordinate (a, b). It is customary for the real axis to coincide with the x-axis of the rectangular coordinate system, and for the imaginary axis to coincide with the y-axis of the rectangular coordinate system.

Imaginary Axis  -  The axis in the complex plane that customarily coincides with the y-axis of the rectangular coordinate system, and on which the imaginary part bı of the complex number a + bı is plotted.

Imaginary Number  -  A number that can be expressed in the form bı, where b is a real number.

Imaginary Part  -  The bı term in every complex number a + bı.

Imaginary Unit  -  The imaginary unit is ı. ı =

.

Modulus  - 

for a complex number a + bı. In the complex plane, it is the distance between the plot of a complex number and the origin.

Polar Form of a Complex Number  -  The polar form of a complex number z = a + bı is this: z = r(cos(θ) + ısin(θ)), where r = | z| and θ is the argument of z.

Real Axis  -  The axis in the complex plane that typically coincides with the x-axis of the rectangular coordinate system, and on which the real part a of a complex numbers a + bı is plotted.

Real Part  -  In a complex number a + bı, a.

Standard Form  -  For a complex number, a + bı.