מממוורן -
HERR
Mean, Mode, M
3, 4, 6, 8, 6, 6, 2
S
14
ini
LIDE
Mean__
Median ___ Mode
Range
WA
WA
.
SHISH
SN
HT
LES
B
une
DELLA
JUIN
.
LEER
TES
inter
SENE
TIN
SESSERE
ESTELLEN
EFRA
LIC

Prove (a) cosh2(x) − sinh2(x) = 1 and (b) 1 − tanh 2(x) = sech 2(x). solution (a) cosh2(x) − sinh2(x) = ex + e−x 2 2 − 2 = e2x + 2 + e−2x 4 − = 4 = . (b) we start with the identity proved in part (a): cosh2(x) − sinh2(x) = 1. if we divide both sides by cosh2(x), we get 1 − sinh2(x) cosh2(x) = 1 or 1 − tanh 2(x) = .