Expression 3: negative "y" equals Start sum from "n" equals 0 to "a" , end sum, StartFraction, left parenthesis, negative 1 , right parenthesis Superscript, "n" , Baseline "x" Superscript, left parenthesis, 2 "n" plus 2 , right parenthesis , Baseline Over left parenthesis, 2 "n" plus 1 , right parenthesis ! , EndFraction−y=a∑n=0−1nx2n+22n+1!
3
Expression 4: "x" equals Start sum from "n" equals 0 to "a" , end sum, StartFraction, left parenthesis, negative 1 , right parenthesis Superscript, "n" , Baseline "y" Superscript, left parenthesis, 2 "n" plus 2 , right parenthesis , Baseline Over left parenthesis, 2 "n" plus 1 , right parenthesis ! , EndFractionx=a∑n=0−1ny2n+22n+1!
4
Expression 5: negative "x" equals Start sum from "n" equals 0 to "a" , end sum, StartFraction, left parenthesis, negative 1 , right parenthesis Superscript, "n" , Baseline "y" Superscript, left parenthesis, 2 "n" plus 2 , right parenthesis , Baseline Over left parenthesis, 2 "n" plus 1 , right parenthesis ! , EndFraction−x=a∑n=0−1ny2n+22n+1!