Given the Fourier series in (−π,π) for f(x)=xcosx, the value of a0 will be
−23π2
(−1)22nn2−1
f(x)=xcosxin(−π,π) ∵f(−x)=(−x)cos(−x) =−xcosx=−f(x) so f(x) is an odd function Now using Fourier series a0=1π∫π−πf(x)dx=0 (∵ f(x) is an odd)
For the function f(x)={−2,−π<x<02,0<x<π The value of an in the Fourier series expansin of f(x) is
Let f(x)={−π,if−π<x≤0π,if0<x≤π be a periodic function of period 2π. The coefficient of sin5x in the Fourier series expansion of f(x) in the interval [−π,π] is
f(x) =π4+2π[cosx12+cos3x32+....]+[sinx1+sin2x2+sin3x3+....] The convergence of the above Fourier series at x = 0 gives