Simplify the expression: 2x + 1 + 7x

Atriangle has side lengths of 15 inches and 30 inches. it also has angles that measure 45º and 20º. which of the following identifies the possible third angle of the triangle? a. 15 in., 65º b. 45 in., 65º c. 17 in., 115º d. 14 in., 115º

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) = .

Solve for x and select the correct answer