Sketch the graph of f by hand and use your sketch to find the absolute and local maximum and minimum values of f. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.)
f(t) = 4 cos(t), -3̃̀/2 ≤ t ≤ 3̀̃/2
absolute maximum value (0, 4)
absolute minimum value (-̀, -4)
local maximum value(s) (0, 4)
local minimum value(s) (-̀, -4), (̀, -4)