() This problem is an example of a differential equation: an equation that relates a function to one or more of its derivatives. You can solve this problem by doing some educated guessing. ("Educated" means "remember what we did in the past.") Suppose f is the function that satisfies for all in its domain, and f'(x)=-(f(x)) f(1) = 1. Then f(x): = Hint: try some of your familiar functions: parabolas hyperbolas exponential tria power