1. The problem statement, all variables and given/known data Ax^2 + Bx + C if neg. infinity < x </= 0 f(x) = x^(3/2) cos (1/x) if 0 <x< pos. infinity Use the definition of the derivative to determine all possible values of the constants A, B and C such that f'(0) exists. Cannot use differentiation formulas. 2. Relevant equations definition of the derivative: lim h->0 of (f(a+h) -f(a))/h 3. The attempt at a solution I used the definition of the derivative for Ax_2 + Bx + C and got an answer of B; but what am I supposed to be looking for? Would f'(0) just be B? and do I have to do anything with the second part ( x^(3/2) cos 1/x)?