# What is Fourier series Theorem?

## What is Fourier series Theorem?

FOURIER THEOREM A mathematical theorem stating that a PERIODIC function f(x) which is reasonably continuous may be expressed as the sum of a series of sine or cosine terms (called the Fourier series), each of which has specific AMPLITUDE and PHASE coefficients known as Fourier coefficients.

## What are the four types of Fourier series?

(i) The Fourier integral:

• (ii) The classical Fourier series:
• (iii) The discrete-time Fourier transform:
• (iv) The discrete Fourier transform:
• What is the Fourier transform of a Fourier series?

The Fourier transform uses an integral (or “continuous sum”) that exploits properties of sine and cosine to recover the amplitude and phase of each sinusoid in a Fourier series. The inverse Fourier transform recombines these waves using a similar integral to reproduce the original function.

### What is Fourier series coefficient?

(1.1) Fourier series representation of a periodic function. Where n is the integer sequence 1,2,3,… In Eq. 1.1, av , an , and bn are known as the Fourier coefficients and can be found from f(t). The term ω0 (or 2πT 2 π T ) represents the fundamental frequency of the periodic function f(t).

### What are the three different forms of Fourier series?

There are two common forms of the Fourier Series, “Trigonometric” and “Exponential.” These are discussed below, followed by a demonstration that the two forms are equivalent.

Is Fourier series and Fourier transform same?

Fourier series is an extension of the periodic signal as a linear combination of sine and cosine, while the Fourier transform is a process or function used to convert signals in the time domain to the frequency domain.

## What is AO in Fourier series?

The coefficients a’s are called the Fourier cosine coefficients (including a0, the constant term, which is in reality the 0-th cosine term), and b’s are called the Fourier sine coefficients.

## What does the Fourier series tell us?

The Fourier Series allows us to model any arbitrary periodic signal with a combination of sines and cosines.

Are Fourier series infinite?

A Fourier series is a way of representing a periodic function as a (possibly infinite) sum of sine and cosine functions. It is analogous to a Taylor series, which represents functions as possibly infinite sums of monomial terms.

### What is the main difference between Fourier series and Fourier transform?

Fourier series is an expansion of periodic signal as a linear combination of sines and cosines while Fourier transform is the process or function used to convert signals from time domain in to frequency domain.

### Why do we need Fourier transform even we have Fourier series?

The Fourier Transform is an important image processing tool which is used to decompose an image into its sine and cosine components. The output of the transformation represents the image in the Fourier or frequency domain, while the input image is the spatial domain equivalent.

How do you calculate a0?

To find the coefficients a0, an and bn we use these formulas:

1. a0 = 12L. L. −L. f(x) dx.
2. an = 1L. L. −L. f(x) cos(nxπL) dx.
3. bn = 1L. L. −L. f(x) sin(nxπL) dx.