1. The problem statement, all variables and given/known data If the domain of f is restricted to the open interval (-pi/2,pi/2), then the range of f(x) = e^(tanx) is A) the set of all reals b the set of positive reals c the set of nonnegative reals d R: (0,1] e none of these (from barron's How to prep for ap calc) 2. Relevant equations Above 3. The attempt at a solution Range of tanx is all real numbers. The range for e^(x) for all real numbers is positive reals. The answers must be b or c Conflict The answer sheet states that b is the correct answer. How come? isn't b and c the same? What's the difference between all positive reals and all non negative reals?