Let's recall the idea of a global extrema. {{CMD_7}}{{CMD_8}} {{CMD_9}} {{CMD_10}} A function {{MATH_11}} has a {{CMD_12}} at {{MATH_13}}, if {{MATH_14}} for every {{MATH_15}} in the domain of the function. {{CMD_16}} A function {{MATH_17}} has a {{CMD_18}} at {{MATH_19}}, if {{MATH_20}} for every {{MATH_21}} in the domain of the function. {{CMD_22}} A {{CMD_23}} is either a global maximum or a global minimum. {{CMD_24}}