8.解:7(x)=m(1-x) T(x)dx c m(l-x)dx ml G/ GI 2G/ 0 X XT5TUl8 2 0 0 2 . ( ) ( ) ( ) ( ) 解：T x m l x T x x G I m l x x G I m l G I p l p l p = − = = − =    d d m x l XT5TU1