If f(x) = 3 cos^2(x) − 6 sin(x) 0 ≤ x ≤ 2π
Find the intervals of increase and decrease, the intervals of concave up and concave down, local
maximum values, local minimum values, and inflection point
review your 1st and 2nd derivative meanings
f' = -6(1+sinx)cosx
f" = 6(sinx-cos(2x))