1. The problem statement, all variables and given/known data Hi, I am currently studying for a exam and I have noticed I have difficulty with squares and roots. I decided to take a problem from an exam so that I can illustrate the problems I am having with it. 2. Relevant equations If f(x) = √(x+1)2 - √(x-1)2 (a) f(x) = 2; (b) f(x) = 2x; (c) f(x) = 2√x; (d) none of (a)-(c). 3. The attempt at a solution My first instict is to remove the squares and the roots so that f(x) = x+1 - (x-1) which in turn gives me the answer (a). This is incorrect. I am guessing it has to do with the fact that x is not defined to be ≥ 0. Any help?