askiitian.expert- chandra sekhar
Last Activity: 15 Years ago
Remember the Argand diagram in which the point (a, b) corresponds to the complex number z = a + ib
When the complex number is written as a + ib where a and b are real numbers, this is known as the Cartesian form.
This point (a,b) can also be specified by giving the distance, r, of the point from the origin and the angle, , between the line joining the point to the origin and the positive x-axis.
By some simple trigonometry it follows that a = r cos and b = r sin
Thus the complex number z can be written as r cos + i r sin
This is known as the polar form of a complex number.
r is called the modulus of z and is the argument of z.
The argument of a complex number is the angle between the positive x-axis and the line representing the complex number on an Argand diagram. It is denoted arg (z).