For my own future reference, in case I lose the bit of paper on which I jotted it.<\/p>\n
In a function of period 2π, a unit step discontinuity in the nth derivative at phase α contributes this to the Fourier series: <\/p>\n
i (in<\/sup> e-ik(t-α)<\/sup> – i-n<\/sup> eik(t-α)<\/sup>) \/ (2πkn+1<\/sup>) <\/p><\/blockquote>\n
I haven’t the skill to prove this for general n<\/i>, but then I’m unlikely to need it for n>2.<\/p>\n","protected":false},"excerpt":{"rendered":"
For my own future reference, in case I lose the bit of paper on which I jotted it. In a function of period 2π, a unit step discontinuity in the nth derivative at phase α contributes this to the Fourier … Continue reading