设函数f(x)以2π为周期,它在 [ -pi ,pi ) 上的表达式为 f(x)= {int )_(0)^pi xsin 2xdx,g(0)+s(pi )=dfrac ({pi )^2}(2)-1:-|||-B _(2)=(int )_(0)^pi xsin 2xdx (pi )+s(0)=dfrac ({pi )^2}(2)-dfrac (3)(2)-|||-_(a)=dfrac (1)(-)(int )_(x)^xxsin 2xdx (pi )+g(0)=dfrac ({pi )^2}(underline { )}underline ( )-|||-"xsin2xdx,