Question

Kim is studying the sale of a particular brand of cereals from the year 2000 to 2010. She writes the following function to model the sale of the cereal S(t), in million dollars, after t years:

S(t) = t2 + 7t + 69

Part A: What does the y-intercept of the graph of the function represent? (4 points)

Part B: What is the reasonable domain of the graph of the function? (3 points)

Part C: What is the average rate of change of the sale of the cereal from the first year to the fourth year? Show your work. (3 points)

Answer 1

@StudyGurl14

Answer 2

@ganeshie8

Answer 3

@JonnyVonny

Answer 4

@jdoe0001

Answer 5

@jdoe0001

Answer 6

@Stormswan

Answer 7

I just need a reasonable domain

Answer 8

and the average rate of change

Answer 9

the y intercept I know

Answer 10

how many years are there between 2000 and 2010 ?

Answer 11

10

Answer 12

0->10
thats 11 years, but the number as such doesn't matter much

Answer 13

So 0=>10?

Answer 14

can we say the reasonable domain is from t=0 to t=10 ?

Answer 15

yes you have it !

Answer 16

Ok thank you are you sure? and one more What is the average rate of change of the sale of the cereal from the first year to the fourth year? Show your work.

Answer 17

acerage rate of change is same as `slope`

Answer 18

start by evaluating the function at t=1 and t=4

Answer 19

S(t) = t^2 + 7t + 69

S(1) = ?
S(4) = ?

Answer 20

So 4-1=3?

Answer 21

not quite

Answer 22

you need to evaluate the function at those t values and plug them in below formula :
\[\large\text{Average rate of change} = \dfrac{S(4) - S(1)}{4-1}\]

Answer 23

1=77
4=113

Answer 24

12?

Answer 25

looks good!

Answer 26

Ok are you sure about the domain part?

Answer 27

aren't you sure ?

Answer 28

No I am just asking, you the math proffessor/expert

Answer 29

becuase when I graph it it doesn't quite make sense

Answer 30

@ganeshie8 ?

Answer 31

could you elaborate on what specific thing that doesn't make sense ?

Answer 32

Ok, when You graph S(t) = t^2 + 7t + 69 you get a parabola, an the domain just doesn't make sense in the graph

Answer 33

domain is x values right ?

Answer 34

look at the graph between t=0 and t=10

Answer 35

ok

Answer 36

the graph starts at t=0, this represents the year 2000, and the value is 69 million dollars

Answer 37

ok, and how does it end on 10?