algebra

savage16

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Which is the graph of the sequence defined by the function f(x) = 100(0.5)x - 1?
On a coordinate plane, 4 points are plotted. The points are (0, 100), (1, 50), (2, 25), (3, 12.5).


On a coordinate plane, 4 points are plotted. The points are (1, 100), (2, 50), (3, 25), (4, 12.5).


On a coordinate plane, 3 points are plotted. The points are (0, 100), (2, 90), (4, 80).


On a coordinate plane, 3 points are plotted. The points are (1, 100), (3, 90), (5, 80).
 

Jomo

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What have you tried? This is a math help site not post your problem and receive an answer. Did you read the forum guidelines?
Please post back telling us where you are stuck.

I will give one hint. When x=0, what does y equal OR when x=1 what does y equal? Remember that y is just another name for f(x) and f(x) is another name for y.
 

savage16

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ive tried everything and still can't get it
 

topsquark

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What is f(3)?

-Dan
 

lev888

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The function doesn't look right. Did you copy it correctly?
 

topsquark

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The function doesn't look right. Did you copy it correctly?
Good point. f(3) = 74, which is not on any of the graphs you provided.

-Dan
 

Jomo

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Otis

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Otis

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Which is the graph of the sequence defined by … 100(0.5)x - 1
Hi savage. The third graph skips the sequence elements given by x=1 and x=3, but that graph would be correct, otherwise, if the definition were given as

f(x) = -100(0.05x - 1)

instead of

f(x) = 100(0.5)x - 1

🤔
 

savage16

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thanks otis
 

Otis

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thanks otis
You're welcome, savage, but that was just an observation that came to me. If I thought some more, I might find a function similar to what you posted that matches one of the other graphs.

Can you post an image of the function definition, as it was given to you? You may have typed it incorrectly, or your materials may contain a mistake.

\(\;\)
 

savage16

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no but all of those are supposed to be on the other side
 

Otis

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… all of those are supposed to be on the other side
Hello. I need help understanding the pronoun 'those', as well as the side you referenced.

All of what are supposed to be on the other side of what?

\(\;\)
 

savage16

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they are supposed to be on the left
 

Otis

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they are supposed to be on the left
Okay, but what are you talking about?

What specifically is supposed to be somewhere else?

:confused:
 

Dr.Peterson

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I suspect the function may be intended to be \(\displaystyle f(x) = 100(0.5)^{x-1}\). It's really important to indicate exponents correctly!
 

savage16

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Dr.Peterson it is indeed suppost to be that is there anyway you can help me
 

Dr.Peterson

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Evaluate f(0), f(1), f(2), and f(3), and see which graph contains the resulting points. Please show what you got when you did that, so we can see if you are evaluating incorrectly.
 

savage16

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Thank you I now know the right answer!
 

Otis

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Hi savage. In the forum guidelines, there's a link to a site that shows how to type math expressions using a keyboard.

We show exponents using the caret symbol ^

100(0.5)^(x - 1)

If the exponent is a single number or symbol, then you may omit the grouping symbols around it.

x^2

😎
 
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