Expression 17: "x" Superscript, "n" , Baseline hyperbolic cosine left parenthesis, "x" , right parenthesisxncoshx
17
Expression 18: "F" Subscript, "n" , Baseline left parenthesis, "x" , right parenthesis equals hyperbolic sine left parenthesis, "x" , right parenthesis Start sum from "k" equals 0 to StartFraction, "n" minus 1 Over 2 , EndFraction , end sum, StartFraction, "n" ! Over left parenthesis, 2 "k" plus 1 ! , right parenthesis , EndFraction "x" Superscript, 2 "k" plus 1 , Baseline minus hyperbolic cosine left parenthesis, "x" , right parenthesis Start sum from "k" equals 0 to StartFraction, "n" minus 1 Over 2 , EndFraction , end sum, StartFraction, "n" ! Over left parenthesis, 2 "k" , right parenthesis ! , EndFraction "x" Superscript, 2 "k" , BaselineFnx=sinhxn−12∑k=0n!2k+1!x2k+1−coshxn−12∑k=0n!2k!x2k
18
Expression 19: "F" Subscript, "n" , Baseline prime left parenthesis, "x" , right parenthesisFn′x