NEED HELP!!! WILL MEDAL!!!
The graph below shows a company's profit f(x), in dollars, depending on the price of erasers x, in dollars, being sold by the company:
Part A: What do the x-intercepts and maximum value of the graph represent? What are the intervals where the function is increasing and decreasing, and what do they represent about the sale and profit? Part B: What is an approximate average rate of change of the graph from x = 1 to x = 4, and what does this rate represent?
where do you think the maximum profit is?
idek man i'm way confused
what do you think? take an educated guess
Dude when i say idk i really do mean it. I have no clue how to answer this. I have no educated guess because i'm not very educated in this
f(x) or y = profit while x is the price
ok
there's a minimum price that gives a maximum profit you move a way from this price the profit goes down in both directions.
alright
now look for the maximum value on the graph
270?
now what price is associated with that? and what does 270 represent?
profit?
yes
Max. profit. This occurs at what price? Read this off the x-axis.
1-8?
now, let's look at the x intercepts
ok
x intercept is when y = 0 or in other words that's when profit is what?
huh? sorry i didn't understand that
yeah so take a look at when x = 0, and 8
x =0 and x = 8 do we have profit?
no?
yes that's correct because y = 0 at these points. x = 8 we can assume that at x = 8 the erasers are too expensive and on one is going to buy them; also at x = 0 well that's relatively easy to conclude why there isn't any profit.
alrighty :D
You understand that?
yep! would that be Part A?
yes
ok now Part B
\[\frac{ \Delta~y }{ \Delta~x } = Average~rate~of~change \]
x = 1 and x = 4 :
find the y point at x = 1 and the y point at x = 4 and find the slope.
x=120 x=270
slope is y=mx+b right?
we just need m
y2-y1/x2-x1
\[\frac{ 270-120 }{ 1-4 } = ? \]
50/3
?
no
150/3
=50
yep, so what this means is that as the price increases from 1 to four dollars
the profit is increasing by an average of 50 dollars
so it represents profit increase?
let's not just focus on a yes or no but do you understand why though? can you tell me why this is the case? this will make things clearer
what's happening from x =1 to x = 4 on our graph?
the profit increases 50
wait can we go back to Part A where it talks about "What are the intervals where the function is increasing and decreasing, and what do they represent about the sale and profit?"
you still there?
yeah so immediately we know in that interval from 1-4 the profit is increasing
what about from x = 4, x = 8 what's happening to the profit.
It's decreasing
why might you think so?
the line parabola is going down
am I wrong?
no you're not. I was asking that because if you notice, the price is getting more expensive so the profit is going down.
ohh ok
so like one reason is possibly that as the price goes up, it's becoming more expensive. right at 4 dollars the profit is the highest then if you make it either more or less expensive to 4 profit goes down.
I'm pretty sure I got it now.
nice
Thank you so much for your help. also thank you for being so patient with me
yeah no problem anytime
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