Determine the values of x and y for the parallelogram.
(3x + 15)
(y +30°
(3x - 15)°

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) = .

Which of the following is best modeled using a linear equation y=ax+b, where a is less than 0?

Cody ran nine miles on his first day of training. the next day he ran 1/8 that distance. how far did he run the second day?