中图苔技术大荸数学系 University of Science and Technology of China DEPARTMENT OF MATHEMATICS 求{l(x)}o,易知: LOx ax (x-x1-1)(x-x+1)……(x )(x +1 (x-x0)…(x-x2-1)(x-x+1)…(x一xn) )(x 记a,(x)=I(x-x)+l(x) o(x) (x1)(x-x1)数 学 系 University of Science and Technology of China DEPARTMENT OF MATHEMATICS 求 n i x i l 0 { ( )} = ，易知： ( ) ( ) ( )( ) ( ) i x ai x x0 x xi 1 x xi 1 x xn l = −  − − − +  − ( ) ( )( ) ( ) 1 i 0 i i 1 i i 1 i n i x x x x x x x x a − − − − =  − +  0 1 1 0 1 1 ( ) ( )( ) ( ) ( ) ( )( ) ( ) i i n i i i i i i i n x x x x x x x x l x x x x x x x x − + − + − − − − = − − − − 0 ( ) ( ) n n i i  x x x = 记 = −  ( ) ( ) ' ( )( ) n i n i i x l x x x x   = −