38. Derive (10.136). (Hint: Use (10.135) and recall that by (10.132), for j 0; 1; ....

38. Derive (10.136). (Hint: Use (10.135) and recall that by (10.132), for j ¼ 0; 1; . . . ;

n þ 1,

~fnðxj þ jÞ  ~fnðxj  jÞ ¼

1 u  d ½ fBð jÞ  fBð j  1Þ:Þ