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Maximum and Minimum. Absolute Maximum or Minimum. A function f has an absolute maximum at c if f(c)≥f(x) for all x in the domain. The number f(c) is called the maximum value of f
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Absolute Maximum or Minimum • A function f has an absolute maximum at c if f(c)≥f(x) for all x in the domain. The number f(c) is called the maximum value of f • A function f has an absolute minimum at c if f(c)≤f(x) for all x in the domain. The number f(c) is called the minimum value of f • These absolute maximum or minimum values are called the extreme values of f
Local (Relative) Maximum or Minimum • Maximum or minimum in a smaller area • Occur at any “hill” or “valley” on a function
Examples: Tell all max and min values for each 1) f(x) = cos x 2) f(x) = x2 3) f(x) = x3 4) f(x) = 3x4 – 16x3+ 18x2 on interval [-1, 4]
Extreme Value Theorem • If f is continuous on a closed interval [ a, b], then f attains an absolute maximum f(c) and an absolute minimum f(d) at some number c and d in [a, b] - more than one extreme may exist - if f is not continuous, may not have an extreme - if the interval is not closed, there may not be an extreme
Fermat’s Theorm • If f has a local maximum or minimum at c, and if f’(c) exists, then f’(c) = 0 • Be careful, at every local max or min the tangent is horizontal, but not every horizontal tangent is a local max or min • Also may be a max or min at locations where f’ does not exist
Critical Number • A number where c in the domain of f such that either f’(c) = 0 or f’(c) does not exist
Example • Find the critical numbers of
Finding Max and Min on a Closed Interval • Find the critical numbers • Evaluate f at each critical number in the interval • Evaluate each endpoint of the interval • The least of these values is the minimum, the most is the maximum
Example Find the absolute maximum and minimum of on the interval [ -1/2, 4]
The Hubble Space Telescope was deployed by the Space Shuttle. A model for the velocity of the shuttle during the mission from liftoff at t=0 to when the boosters were jettisoned at t=126s is given by Use this model to estimate the maximum and minimum values of acceleration.