A math contest for college students, answer what the second kind of behavior is, and ask God for guidance! !
①x∈(nπ→(n+ 1)π), | sinx |/x ≤| sinx |/[(n+1) π], so ∫| sinx |/xdx ≤∫| sinx.
② n π→ (n+ 1) π, ∫| sinx | dx represents the area enclosed by sinx and x axis of a π period =0→π, the area of sinx.