>>96

∫f(x)dx = (1/a)∫sin(ax)/x dx = (1/a)Si(ax),

∫{f(x)}^2 dx = ∫{sin(ax)/ax}^2 dx
　= - {sin(ax)}^2 /(aax) + (1/a)∫sin(2ax)/x dx
　= - {sin(ax)}^2 /(aax) + (1/a)Si(2ax),

にて簡単