# Complex no's & Quadratic equations

Complex no's & Quadratic equations

We have learnt many methods to find the square root of a number.But when a negative number root is to be determined then comes the problem.Here a new imaginary unit 'i' is introduced

A complex number is a number that can be expressed in the form a + bi, where a and b are real numbers and i is the imaginary unit, which satisfies the equation *i ^{2}*= −1. In this expression, a is the real part and b is the imaginary part of the complex number. Complex numbers extend the concept of the one-dimensional number line to the two-dimensional complex plane by using the horizontal axis for the real part and the vertical axis for the imaginary part. The complex number a + bi can be identified with the point (a, b) in the complex plane. A complex number whose real part is zero is said to be purely imaginary, whereas a complex number whose imaginary part is zero is a real number. In this way the complex numbers contain the ordinary real numbers while extending them in order to solve problems that cannot be solved with real numbers alone.

Now lets know where are complex numbers used?

Complex numbers have essential concrete applications in a variety of scientific and related areas such as signal processing,control theory, electromagnetism, fluid dynamics,quantum mechanics, cartography, and vibration analysis. Some applications of complex numbers are:

Complex no's and Quadratic equations

Now you are able to say what are complex numbers and where they are to be used.

Basics are once again clearly explained by this video.

Watch it!!

Here I come with a set of solved problems which are self explanatory