1. The problem statement, all variables and given/known data Find if it is true that the general solution to : y'' - y' = 0, where y(x), can be written as : y(x) = c1 cosh(x) + c2 sinh(x), where c1 and c2 are real arbitrary constants. 2. Relevant equations differential equation solving 3. The attempt at a solution I just want to know what the h's mean at the end of sin and cos.