- Graph of a Function
To sketch the graph of a differentiable function, follow these steps: - Find
and determine the values of where . - Check the signs of
on both sides of these -values and create an increasing/decreasing chart (sign chart). - Use the information about the function’s increasing/decreasing behavior, local maximum/minimum points, and intercepts with the coordinate axes to sketch the general shape of the graph.
- Maximum and Minimum Values of a Function
When a functionis continuous on a closed interval , its maximum and minimum values can be found using the following steps: - Find the local maximum and minimum values of
in the open interval . - Evaluate the function at the endpoints
and . - The largest of these values is the maximum, and the smallest is the minimum.
-
  - i.Local maximum and minimum values are not always the global maximum and minimum.
- ii.If
is continuous on a closed interval, there will always be exactly one global maximum and one global minimum, though there may be several local extrema. - iii.If a continuous function
has only one extreme value (either a maximum or a minimum) on the interval : -
If the extreme value is a local maximum, then
(local maximum) (global maximum) -
If the extreme value is a local minimum, then
(local minimum) (global minimum) - Application of Maximum and Minimum Values of a Function
To find the maximum or minimum value of quantities like length, area, or volume: - Define an appropriate variable as the unknown
. - Express the quantity to be maximized or minimized as a function of
. - Differentiate the function and find the critical points (extrema).
- Ensure that the maximum or minimum value is within the allowable range for
, then determine the desired maximum or minimum value.
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