let g(x) = xf(x)g'(x) = xf'(x) + f(x)∫xf'(x)dx= ∫g'(x)dx -∫f(x) dx= g(x) - sinx/x + Cf(x) = (sinx/x)' = -sinx/x^2+cosx/x =(-sinx + xcosx)/x^2xf(x) = (-sinx + xcosx)/...