let f(x) = 2-x if x<= 1 x^2 - 2x + 2 if x > 1 Is f diff at x = 1? At first I would say yes because f(x) is continuous at x = 1. But when I graph f '(x) it is obvious that the function is not differentiable at x = 1. My questions is.... is there another way to determine if f is diff at x = 1 other than graphing???? thank you.