A rate of change relates a change in an output quantity to a change in an input quantity. The average rate of change is determined using only the beginning and ending data. See
[link] .
Identifying points that mark the interval on a graph can be used to find the average rate of change. See
[link] .
Comparing pairs of input and output values in a table can also be used to find the average rate of change. See
[link] .
An average rate of change can also be computed by determining the function values at the endpoints of an interval described by a formula. See
[link] and
[link] .
The average rate of change can sometimes be determined as an expression. See
[link] .
A function is increasing where its rate of change is positive and decreasing where its rate of change is negative. See
[link] .
A local maximum is where a function changes from increasing to decreasing and has an output value larger (more positive or less negative) than output values at neighboring input values.
A local minimum is where the function changes from decreasing to increasing (as the input increases) and has an output value smaller (more negative or less positive) than output values at neighboring input values.
Minima and maxima are also called extrema.
We can find local extrema from a graph. See
[link] and
[link] .
The highest and lowest points on a graph indicate the maxima and minima. See
[link] .
Section exercises
Verbal
Can the average rate of change of a function be constant?
Yes, the average rate of change of all linear functions is constant.
t he silly nut company makes two mixtures of nuts: mixture a and mixture b. a pound of mixture a contains 12 oz of peanuts, 3 oz of almonds and 1 oz of cashews and sells for $4. a pound of mixture b contains 12 oz of peanuts, 2 oz of almonds and 2 oz of cashews and sells for $5. the company has 1080
Lairene and Mae are joking that their combined ages equal Sam’s age. If Lairene is twice Mae’s age and Sam is 69 yrs old, what are Lairene’s and Mae’s ages?