Which graph represents the solution to the inequality 11 < y - 43?
50 51 52 53 54 55 56 57 58 59 60
0
50 51 52 53 54 55 56 57 58 59 60
o
-35-34-33-32 -31 -30 -29 -28 °7 -26 -25

-35 -34 -33 -32 -31 -30-29 -28 -27 -26 -25

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) = .