1. The problem statement, all variables and given/known data Determine the values of the number "a" for which the function "f" has no critical number. 2. Relevant equations If I'm not mistaken, this should be the result for differentiation: 3. The attempt at a solution Critical points are either where function derivation is not defined (does not exists), OR where the derivation is equal to zero. This is my answer; although, it seems to be a very complicated and somehow incorrect: "a" should not be these values, so "f" will not have any critical number.