Expression 6: negative hyperbolic co tangent "x" equals negative StartFraction, cosh "x" Over sinh "x" , EndFraction equals negative StartFraction, "e" Superscript, "x" , Baseline plus "e" Superscript, negative "x" , Baseline Over "e" Superscript, "x" , Baseline minus "e" Superscript, negative "x" , Baseline , EndFraction equals negative StartFraction, "e" Superscript, 2 "x" , Baseline plus 1 Over "e" Superscript, 2 "x" , Baseline minus 1 , EndFraction equals negative StartFraction, 2 Over "e" Superscript, 2 "x" , Baseline minus 1 , EndFraction minus 1−cothx=−coshxsinhx=−ex+e−xex−e−x=−e2x+1e2x−1=−2e2x−1−1