What are imaginary numbers and where are they used?

Answer 1

This is related to complex numbers. Real numbers can be represented on a line. Complex numbers are a type of vector, in two dimensions. The way complex numbers are usually represented, the horizontal axis is the "real" part, while the vertical axis is called the "imaginary" part. Don't give too much importance to the words "real" and "imaginary"; they are used for historical reasons. Thus, any point on the complex plane is made up of two components - a real part and an imaginary part - for example, 3 + 4i, or -5 - 2i. The first part is the "real" part, and the second, with the "i" at the end, the "imaginary" part. Addition of complex numbers is quite straightforward, just add the components. For multiplication, i2 is defined as -1. Other than that, just do a normal polynomial multiplication.

Where are complex numbers used? In a variety of areas, including electricity, quantum mechanics, art (take a look at fractals for some examples!), and many other areas.