y(x)=2cX=∑2x=2∑ o(1Cr(v+1)2nty n-0 n-0 22nl(+n+1) ∴类似的取P=P2=,则得 h2(x)=2(yC(++1),2m )2"n!I(V+n+1)∴ 2 2 0 1 2 2 0 0 0 (-1) ( 1) ( ) 2 ! ( 1) n k n n k n n k n n C y x C x C x x n n n n n n n ¥ ¥ ¥ + + + = = = G + = = = G + + å å å 类似的取 2 r = = r n- ，则得 0 2 - 2 2 0 (-1) (- 1) ( ) 2 ! (- 1) n n n n C y x x n n n n n ¥ = G + = å G + +