## What is the sum of Fourier series?

σn(x)=n∑k=0(1−kn+1)Ak(x).

### How do you find the cosine of a Fourier series?

1. Find the Fourier cosine series of f(x)=x on [0,L]. an=2L∫L0xcosnπxLdx=2nπ[xsinnπxL|L0−∫L0sinnπxLdx]=−2nπ∫L0sinnπxLdx=2Ln2π2cosnπxL|L0=2Ln2π2[(−1)n−1]={−4L(2m−1)2π2,if n=2m−1,0,if n=2m. C(x)=x,0≤x≤L.

#### What is the Fourier transform of cosine?

Therefore, the Fourier transform of cosine wave function is, F[cosω0t]=π[δ(ω−ω0)+δ(ω+ω0)] Or, it can also be represented as, cosω0tFT↔π[δ(ω−ω0)+δ(ω+ω0)] The graphical representation of the cosine wave signal with its magnitude and phase spectra is shown in Figure-2.

**What is the general form of the Fourier cosine expansion?**

The cosine form Fourier series is also known as polar form Fourier series or harmonic form Fourier series. The trigonometric Fourier series of a function x(t) contains sine and cosine terms of the same frequency. That is, x(t)=a0+∞∑n=1ancosnω0t+bnsinnω0t…( 1)

**Why Fourier series representation of any signal is done in sine and cosine terms?**

The objective of constructing a Fourier series is to approximate any function with a period P. This can be done buy using sines and cosines that have any period P/n where n is an integer >= 0. The larger the value of n the better the approximation can be.

## How do you find the sum of cosine series?

Cosine sum cos(a)=cos(a+d)=cos(a+2d)…

### How do you find cosine and sine series?

an=2L∫L0f(t)cos(nπLt)dt. The series ∑∞n=1bnsin(nπLt) is called the sine series of f(t) and the series a02+∑∞n=1ancos(nπLt) is called the cosine series of f(t).

#### What is the relationship between Fourier series and Fourier transform?

The Fourier series is used to represent a periodic function by a discrete sum of complex exponentials, while the Fourier transform is then used to represent a general, nonperiodic function by a continuous superposition or integral of complex exponentials.

**What is Fourier transform of sine?**

The Fourier Transform of the Sine and Cosine Functions Equation [2] states that the fourier transform of the cosine function of frequency A is an impulse at f=A and f=-A. That is, all the energy of a sinusoidal function of frequency A is entirely localized at the frequencies given by |f|=A.

**How do you find the sum of a trig series?**

Generally we use two methods to find the summation of the trigonometric series: 1. Method of Differences, and 2. C + iS Method. Thus we express the sum of the given series in the form of A + iB and then equating the real and imaginary parts, we get the values of C and S.

## Does the Fourier transform use sine or cosine?

I know that Fourier transform returns frequency spectrum and it contains both Sine & Cosine terms as “imaginary and real terms”. However, we also have individual Sine and Cosine transforms.

### How is the Fourier series sum calculated at a point when the signal is discontinuous?

Explanation: When there is a point of discontinuity, the value of the function at that point is found by taking the average of the limit of the function in the left hand side of the discontinuous point and right hand side of the discontinuous point.

#### Can Fourier series be applied on discontinuous function?

In this work, Fourier-series representation of a discontinuous function is used to highlight and clarify the controversial problem of finding the value of the function at a point of discontinuity.

**How do you sum sin and cos?**

Label two more points: A at an angle of (α−β) from the positive x-axis with coordinates (cos(α−β),sin(α−β)); and point B with coordinates (1,0)….Using the Sum and Difference Formulas for Cosine.

Sum formula for cosine | cos(α+β)=cosαcosβ−sinαsinβ |
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Difference formula for cosine | cos(α−β)=cosαcosβ+sinαsinβ |

**Why do we use sin and cos in Fourier series?**

## What is the formula for cosine series?

The series ∑∞n=1bnsin(nπLt) is called the sine series of f(t) and the series a02+∑∞n=1ancos(nπLt) is called the cosine series of f(t).

### What is the difference between FT and FS?

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.