If f is integrable on [tex](-\infty, \infty) = E[/tex] then [tex]\lim_{n\rightarrow\infty} \int_E f(x)cos(nx) = 0 [/tex](adsbygoogle = window.adsbygoogle || []).push({});

it's supposed to be easy if f is a step function & then i can use another problem that was part of the homework, but i can't seem to figure out how that would work.....

(ps- maybe i shouldn't call myself fourier jr if i'm stuck on a problem like this :uhh: )

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# Help with Riemann-Lebesgue theorem pls

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