Soru
a) Consider the periodic function f(x) defined by : f(x)= ) 0,&-pi lt xlt 0 x,&0leqslant xlt pi i.Sketch the function in the interval [-3pi ,3pi ] ii. Find the Fourier series expansion for f(x) Hence sum the series: 1+(1)/(3^2)+(1)/(5^2)+(1)/(7^2)+...
Çözüm
4.2
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Hülya
Elit · 8 yıl öğretmeni
Uzman doğrulaması
Cevap
Let's correct and complete the Fourier series expansion for \( f(x) \) and sum the series.### i. Sketch the function in the interval
The function \( f(x) \) is defined as:
This means \( f(x) \) is zero for
and \( f(x) = x \) for
. To sketch this:- For
, \( f(x) = 0 \).- For
, \( f(x) = 0 \).- For
, \( f(x) = x \).- For
, \( f(x) = 0 \).### ii. Find the Fourier series expansion for \( f(x) \)The Fourier series expansion of a periodic function \( f(x) \) with period
is given by:
Where the coefficients
and
are given by:
For \( f(x) \) defined as:
#### Compute
:
Since \( f(x) = 0 \) for
:
#### Compute
:
Since \( f(x) = 0 \) for
:
#### Compute
:\[ b_n = \frac{1}{\pi}