수식 2: "f" left parenthesis, "x" , right parenthesis equals Start sum from "n" equals 0 to "k" , end sum, StartFraction, left parenthesis, negative 1 , right parenthesis Superscript, "n" plus 1 , Baseline left parenthesis, "x" minus pi , right parenthesis Superscript, 2 "n" , Baseline Over left parenthesis, 2 "n" , right parenthesis ! , EndFractionfx=k∑n=0−1n+1x−π2n2n!