84) Working alone, Lisa can dig a 10 ft by 10
ft hole in six hours. One day her friend
Norachai helped her and it only took 2.73
hours. How long would it take Norachai
to do it alone?

Find the smallest number by which the given number should be divided to make a perfect cube(with steps or the answer will get reported) a.108 b.2187

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) = .

Askate shop rents roller skates as shown on the table below. which graph and function models this situation?