นิพจน์ 3: Start sum from "n" equals 0 to 6, end sum, left parenthesis, negative 1 , right parenthesis Superscript, "n" , Baseline left parenthesis, StartFraction, "x" Superscript, left parenthesis, 2 "n" , right parenthesis , Baseline Over left parenthesis, 2 "n" , right parenthesis ! , EndFraction , right parenthesis minus cosine left parenthesis, "x" , right parenthesis6∑n=0−1nx2n2n!−cosx