/ x\ asinh\e /
x e ------------- __________ / 2*x \/ 1 + e
/ 2*x \ | e | x |1 - --------|*e | 2*x| \ 1 + e / ----------------- __________ / 2*x \/ 1 + e
/ 2*x 4*x \ | 4*e 3*e | x |1 - -------- + -----------|*e | 2*x 2| | 1 + e / 2*x\ | \ \1 + e / / ------------------------------- __________ / 2*x \/ 1 + e