Fourier Series - Introduction

tell me if any problems or errors http://www.geocities.com/burnyboy2004/ 26/02/09

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[meepington]

Video really helped me understand the concepts. You made one small error. While computing b_n forgot to multiply the result of the integral by 1/pi. The error is at 2:46.

[burny1]

@meepington thanks

[Ekpyrotic]

Mistakes and improvements.

1. You assumed that L/2=π, therefore the scalar which multiplies the integration is given as 1/π instead of the more general 1/l. This would be confusing for people learning.

2. Why do the integration by parts when you can recognise the function is odd? f(t)=t is odd, f(t)=cos(nt) is even. So f(t)=t.cos(nt) is odd. So, of course, the integral is going to be zero between [-l, l).

[burny1]

(1) I see your point but this is the way i was taught it. Looking through aswell i see all the questions i have been given by the lecturer are from (-π,π). With (2) I have not taught odd and even functions yet and i was just using the formula as they have just been introduced. I do think checking if its odd and even is greatly useful so have added the annotation in there are there will probably not be any more fourier series videos due to the module being finished. thanks for your interest

[kraknius]

this is much clearer now thanks, i'm only a little bit unsure of the odd and even bit, but that's so much better than not having a clue at all lol

[89rosepetal]

matt try standing back

[Ekpyrotic]

Thanks for the swift response. I expect you have exams coming up like me (St Andrews), I bid you good luck.