Here, is known as the complex modulus (or sometimes the complex norm) and is known as the complex argument or phase . The plot above shows what is known as an Argand diagram of the point , where the dashed circle represents the complex modulus of and the angle represents its complex argument . Historically, the geometric representation of a complex number as simply a point in the plane was important because it made the whole idea of a complex number more acceptable. In particular, "imaginary" numbers became accepted partly through their visualization.