Discuss the below:
Q: Suppose f(x) = ln(2 + cos x) on the interval (0, 2pi).
a) Calculate f' (x) and f" (x).
b) Find the interval(s) on which the function f is increasing.
c) Find all extreme values of f and the values of x at which they occur.
d) Find the interval(s) on which the function f is concave up?