若令x1=x0,xm X-X x1≤x≤x(j=0,…,m) X-X 几.(x ≤x≤x1(j=0, 0, els 则4(x)是分段一次的连续函数且满足条件若令 则 是分段一次的连续函数且满足条件 1 1 1 1 1 1 , ( 0 1, , ); ( ) , ( 0 1, , ; 0 j j j j j j j j j j j x x x x x j n x x x x x x x x j n x x − − − + + + − = − − = = − , , ) , else 1 0 1 , , n n x x x x − + = = ( ) j x