Question

I need help with 3 math questions and before you help please keep in mind that I have problems in math and I really need a patient understanding person to help me I dont understand anything in this math class so please try to understand and help me. (attached pictures).

Answer 1

\[f(x)\] is the profit
the \(x\) intercepts are where the profit is zero, i.e. no money is made

Answer 2

so if they cost \(\$0\) then they make no money, and if they cost \(\$4\) then evidently they are too expensive, and no one buys them and they still make no money

Answer 3

it is clear where the \(x\) intercepts are? and how i knew they were at 0 and 4?

Answer 4

yeah but i dont get what part you are answering? sorry if i sound dumb or slow

Answer 5

first question asks "what do the x intercepts and maximum of the graph represent"
i was going slow and only tackled the "x intercepts" part

Answer 6

no not dumb or slow, just confused
do you understand what the graph is telling you? i.e. how to read the graph? if the answer is "no" that is okay, i can maybe explain

Answer 7

Ahhhh okay lol sorry thanks and yeah could you just refresh me a little on that if you dont mind (:

Answer 8

ok so the x axis in this case represents cost or "price of the book" and the y axis represents "profit"
do you see the point on the graph \((2,300)\)?

Answer 9

i hope that is clear, it is the point right at the top of the curve
you do see it right?

Answer 10

yes i see it

Answer 11

ok what that means in this case is that if the cost of the book is $2, then the they make $300 in profit

Answer 12

that is the second part of the answer to question 1, because that is the maximum value of the curve
in english,
if the cost of the book is $2 then the profit is $300 and that is the most profit they can make.
clear ?

Answer 13

oka yeah thanks clear (:

Answer 14

now how about increasing/ decreasing?

Answer 15

this may be confusing because you need to answer in terms of \(x\) i.e. cost of the book, not \(y\) profit
if you look at the graph you see it is increasing for values of \(x\) from \(0\) to \(2\) i.e. on the interval \(0<x<2\) and decreasing on \(2<x<4\)

Answer 16

okay yeah i think i can see that

Answer 17

ok then that takes care of part 1

Answer 18

okay sorry back I had to refresh my tab and get my notebook.

Answer 19

ok are we good with part 1?

Answer 20

um well i dont get as to what the intervals represent about the sale and profit

Answer 21

if the cost goes from zero dollars to 2 dollars, the profit increases from $0 to $300
as the cost increases from 2 to 4, the profit declines from $300 to $0

Answer 22

okay thank you (:

Answer 23

yw
how about part B

Answer 24

could you refresh me on what the domain is? sorry

Answer 25

domain is the x values
no need to be sorry
range is the y values

Answer 26

so the question is, for which values of x, i.e. .for which cost, is the profit $220 or more

Answer 27

it is hard for me to see it on the graph, but it looks like from about $1 to $3
do you see that?

Answer 28

yeah i do see it

Answer 29

so that would be the answer to part 2
from $1 to $2 would be the domain for that amount of profit, i.e. \(1\leq x\leq3\)

Answer 30

okay thank you (:

Answer 31

how about C?

Answer 32

sorry about this again but refresh me on the rate of change?

Answer 33

sure
it is the change in y divided by the change in x

Answer 34

in this case it is pretty easy
the change in y is \(0-300=-300\) and the change in \(x\) is \(4-2=2\) so the average rate of change is
\[\frac{0-300}{4-2}=\frac{-300}{2}=-150\]

Answer 35

Okay i think i understand that, once again thank you (:

Answer 36

yw

Answer 37

could you help me with my other 2 of so would you like me to post them on here or a new post?

Answer 38

*if

Answer 39

your choice

Answer 40

i will make a new one and tag you in it so its easier for me to go back (:

Answer 41

good idea