Checking your Fourier Series coefficients

WolfOfTheSteps
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When you compute the Fourier series coefficients for a function, is there any quick way to check if your answer is correct or at least reasonable?Thanks.
 
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I would graph it using plotting software.

You could also pick a random value of x and calculate the first few terms by hand.
 
So I guess that means there is no quick way to tell, when you are taking a test or something?
 
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It's a good question. Maybe someone else can give you better advice.
 
There is not really an easy shortcut, but one thing you could do is Check that f(0)= \left( \sum_{n=0}^{\infty} a_n \right) - \frac{a_0}{2}

That only checks your a_n, for b_n all I can offer is to recheck your derivation. Good Luck lol
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
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