Maren is painting some doors that are all the same size. she used 3 liters of paint to cover 9/5 doors. how many liters of paint are needed for 1 door?

One integer is 8 times another. if the product is 72, then find the integers

Can someone check if i did this correct. it’s number 4 if you’re wondering.

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) = .