# algebra

#### savage16

##### New member
Which is the graph of the sequence defined by the function f(x) = 100(0.5)x - 1?

#### Jomo

##### Elite Member
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

##### New member
ive tried everything and still can't get it

What is f(3)?

-Dan

#### lev888

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

#### topsquark

##### Full Member
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

##### Elite Member
Good point. f(3) = 74, which is not on any of the graphs you provided.

-Dan
I think that you might want to try that again.

#### Otis

##### Senior Member
I think [Dan] might want to try that again.
Looks like Dan may have used 0.25 instead of 0.5

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#### Otis

##### Senior Member
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)

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

thanks otis

#### Otis

##### Senior Member
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

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

#### Otis

##### Senior Member
… 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

##### New member
they are supposed to be on the left

#### Otis

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

What specifically is supposed to be somewhere else?

#### Dr.Peterson

##### Elite Member
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

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

#### Dr.Peterson

##### Elite Member
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

##### New member
Thank you I now know the right answer!

#### Otis

##### Senior Member
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