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help on 10-S2-Q4

I am stuck on part ii) and was wondering if I could have hint on the right direction to go in.
So far I have tried doing substitution of x=u-1/2 in order to get the limits similar to part i), and then was trying to do integration by parts. However I am struggling to simplify the sin(1/x) part into f(a-x).

Thank you.

I meant I tried u=x-1/2

This part of the question is not directly related to the previous part so you don't want to try to reduce the integral to the form of $I$ in part (i). However, if I write the integral in the form $$J=\int_{1/b}^{b} \frac{g(x)}{x(g(x)+g(1/x))}\,\mathrm{d}x \quad \text{where} \quad g(x)=\sin(x),\,b=2,$$perhaps you can spot a helpful substitution that will allow you to use a similar trick that you used in evaluating $I$ in part (i).

I used the substitution u=1/x and it worked.
Thank you very much! :)

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