1. The problem statement, all variables and given/known data Find the extremizing (maximum) value of the function f(x) = sin x / x using Newton's 1D method. 2. Relevant equations 3. The attempt at a solution I know the maximum point in this equation is (0, 1). When I differentiated the equation twice and used the formula above, I managed to get a converging value of x at 4.49 radians and my corresponding value of f(x) is -0.217. I checked this using wolframalpha as well, and the converging value is 4.49 radians also. I'm sure I didn't make any silly algebraic errors, so what could be wrong here?