Problem 3. In this problem, we will determine a closed formula for the the n-th partial sum of a Fourier series of a function f : (-π, π) → R. You will need the following trigonometric identity (which you do not have to prove): 1 +cos u+cos 2u + ...cos nu = sin(n + 1)u 2 sin(u/2) 2 Suppose that f has period 27, with the Fourier series ao f(x) ~ 2 ∞ +Σ (ak cos(kx) + bk sin(kx)). k=1 If sn(x) denotes the n-th partial sum of this series, show that n 1 ao Sn(x) : 2 + Σ (a^ cos(kx) + by sin(kx)) ==—=—= √ f(t) sin[(n + 1)(t − x)] 2 sin((t - x)) dt. k=1

Calculus: Early Transcendentals
8th Edition
ISBN:9781285741550
Author:James Stewart
Publisher:James Stewart
Chapter1: Functions And Models
Section: Chapter Questions
Problem 1RCC: (a) What is a function? What are its domain and range? (b) What is the graph of a function? (c) How...
icon
Related questions
Question
Problem 3.
In this problem, we will determine a closed formula for the the n-th partial sum of a
Fourier series of a function f : (-π, π) → R. You will need the following trigonometric identity (which you
do not have to prove):
1
+cos u+cos 2u + ...cos nu =
sin(n + 1)u
2 sin(u/2)
2
Suppose that f has period 27, with the Fourier series
ao
f(x)
~
2
∞
+Σ (ak cos(kx) + bk sin(kx)).
k=1
If sn(x) denotes the n-th partial sum of this series, show that
n
1
ao
Sn(x) :
2
+ Σ (a^ cos(kx) + by sin(kx)) ==—=—= √
f(t)
sin[(n + 1)(t − x)]
2 sin((t - x))
dt.
k=1
Transcribed Image Text:Problem 3. In this problem, we will determine a closed formula for the the n-th partial sum of a Fourier series of a function f : (-π, π) → R. You will need the following trigonometric identity (which you do not have to prove): 1 +cos u+cos 2u + ...cos nu = sin(n + 1)u 2 sin(u/2) 2 Suppose that f has period 27, with the Fourier series ao f(x) ~ 2 ∞ +Σ (ak cos(kx) + bk sin(kx)). k=1 If sn(x) denotes the n-th partial sum of this series, show that n 1 ao Sn(x) : 2 + Σ (a^ cos(kx) + by sin(kx)) ==—=—= √ f(t) sin[(n + 1)(t − x)] 2 sin((t - x)) dt. k=1
Expert Solution
steps

Step by step

Solved in 1 steps with 5 images

Blurred answer
Similar questions
Recommended textbooks for you
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781285741550
Author:
James Stewart
Publisher:
Cengage Learning
Thomas' Calculus (14th Edition)
Thomas' Calculus (14th Edition)
Calculus
ISBN:
9780134438986
Author:
Joel R. Hass, Christopher E. Heil, Maurice D. Weir
Publisher:
PEARSON
Calculus: Early Transcendentals (3rd Edition)
Calculus: Early Transcendentals (3rd Edition)
Calculus
ISBN:
9780134763644
Author:
William L. Briggs, Lyle Cochran, Bernard Gillett, Eric Schulz
Publisher:
PEARSON
Calculus: Early Transcendentals
Calculus: Early Transcendentals
Calculus
ISBN:
9781319050740
Author:
Jon Rogawski, Colin Adams, Robert Franzosa
Publisher:
W. H. Freeman
Precalculus
Precalculus
Calculus
ISBN:
9780135189405
Author:
Michael Sullivan
Publisher:
PEARSON
Calculus: Early Transcendental Functions
Calculus: Early Transcendental Functions
Calculus
ISBN:
9781337552516
Author:
Ron Larson, Bruce H. Edwards
Publisher:
Cengage Learning