Absolute maximum value
which is when f(c) is the largest value that f attains across the entire domain.
textbook:
absolute maximum value of f on D if f(c) ≥ f(x) for all x in D
D = domain
Absolute minimum value
which is when f(c) is the smallest value that f attains across the entire domain.
absolute minimum value of f on D if
f(c) ≤ f(x) for all x in D
D = domain
local maximum value
of f if f(c) ≥ f(x) when x is near c
local minimum value
of f if f(c) ≤ f(x) when x is near c
Extreme Value theorem
If f is continuous on a closed interval [a,b], then f has an absolute maximum value f(c) and an absolute minimum value f(d) at some numbers c and d in [a,b]