∫(1/x^2)(sin(1/x))dx
=∫-sin(1/x)d(1/x)
=cos(1/x)+C0
∫[2/π,+∞] (1/x^2)sin(1/x)dx
=lim(x→∞) cos(1/x)-cos( π/2)
=cos0=1搞错 明白了 谢谢