Chapter 12 - Fourier Series Flashcards
Fourier series of f (x)
S (x)= (a0/2) + sum (1 to inf) of (an cosnx + bn sinnx)
A0
(1/pi) * integral (-pi to pi) f (x) dx
An
1/pi * integral (-pi to pi) f(x) cosnx dx
Bn
1/pi * integral (-pi to pi) f(x) sinnx dx
What does it mean if S (x) is periodic, with fundamental period 2pi?
S (x + 2k*pi) = s (x) for all x in r and any integer k
Even function
F (-x) = f (x) for all x
Odd function
F (-x) = -f (x) for all x
What does f (x) equal when f (x) is even?
(A0/2) + sum (1 to inf) of (an*cosnx)
What does f (x) equal when f (x) is odd?
Sum (1 to inf) of (bn*sinnx)
Dirichlet conditions
F (x) must be single-valued and continuous, except for at a finite number of points at which it has finite discontinuities.
F (x) must only have a finite numver of maxima and minima on the interval