Find the abs max and abs min values of the function
f(x) = -2x^2 + 3x + 6x^(2/3) + 2.
The Attempt at a Solution
So the candidates are the endpoints, where f'(x) = 0, and where f(x) DNE.
f(-1) = 3
f(3) = 5.481
For the derivative of the function, i got to f(x) = -4x + 3 + (1/(4x^3)). Set it to 0. But I can't find what x is. How do I use my calculator to find this? For the past five years, I haven't been allowed to use a calculator for my math courses, so I don't really know how to do anything with it. This year, I can use one, but I'm not sure how to use it to find x.
Also, f('x) DNE at x = 0. How do I use that information to determine the value to put that as a candidate for the abs max and abs min?