# Need little help listing from smallest to largest

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• Dec 12th 2012, 09:11 PM
theunforgiven
Need little help listing from smallest to largest
Hey,
I need little help with this problem:

http://img826.imageshack.us/img826/2531/digitalw.jpg
Can someone please show me how to find the smallest one (or just anyone for that matter?) I'm not looking for the final answer, just show me to find any of them and I'll take it from there. (Hi) I do have an example in the book similar to this one, but it only gives the final answer, which is not what I'm looking for.
• Dec 12th 2012, 09:25 PM
MarkFL
Re: Need little help listing from smallest to largest
First, can you see that c) is negative and d) is positive?
• Dec 12th 2012, 09:33 PM
theunforgiven
Re: Need little help listing from smallest to largest
Quote:

Originally Posted by MarkFL2
First, can you see that c) is negative and d) is positive?

I can't, mainly because I'm not sure how to plug 2 and 1 for c) or 1 and -1 for d)
• Dec 12th 2012, 09:41 PM
MarkFL
Re: Need little help listing from smallest to largest
You don't need to, nor can you, plug in these values since you are not told what $f(x)$ actually is. You are being expected to observe that the area between the function and the x-axis represents the magnitude of the definite integral, which is positive where $0 and negative when $f(x)<0$.

So, which one would you say is the largest in value out of all the choices and why?
• Dec 12th 2012, 09:50 PM
theunforgiven
Re: Need little help listing from smallest to largest
Quote:

Originally Posted by MarkFL2
You don't need to, nor can you, plug in these values since you are not told what $f(x)$ actually is. You are being expected to observe that the area between the function and the x-axis represents the magnitude of the definite integral, which is positive where $0 and negative when $f(x)<0$.

So, which one would you say is the largest in value out of all the choices and why?

This is starting to make sense. I'd say e) is the largest, given it combines the area for d) and b) (although b) is negative, it turns positive because of the absolute value.)
• Dec 12th 2012, 09:53 PM
MarkFL
Re: Need little help listing from smallest to largest
Yes, that's absolutely correct! :D Now, which would you say is the smallest and why?
• Dec 12th 2012, 09:56 PM
theunforgiven
Re: Need little help listing from smallest to largest
Quote:

Originally Posted by MarkFL2
Yes, that's absolutely correct! :D Now, which would you say is the smallest and why?

I'd say b) is the smallest, given its the only negative out of them all.
• Dec 12th 2012, 09:58 PM
Prove It
Re: Need little help listing from smallest to largest
Quote:

Originally Posted by theunforgiven
I'd say be is the smallest, given its the only negative out of them all.

It's not the only negative, but it takes up the most area below the x axis. So yes, it's the smallest...
• Dec 12th 2012, 09:59 PM
theunforgiven
Re: Need little help listing from smallest to largest
Quote:

Originally Posted by Prove It
It's not the only negative, but it takes up the most area below the x axis. So yes, it's the smallest...

Oh my bad. C) is negative as well. :D
• Dec 12th 2012, 10:06 PM
theunforgiven
Re: Need little help listing from smallest to largest
So, the final answer would be b<c<f<a<d<e
• Dec 12th 2012, 10:09 PM
Prove It
Re: Need little help listing from smallest to largest
Looks good to me :)
• Dec 12th 2012, 10:12 PM
MarkFL
Re: Need little help listing from smallest to largest
How about f)? What would you say its value is?

So, given what you have so far, can you now give them in the required order?

edit: I was too slow. (Rofl)
• Dec 12th 2012, 10:29 PM
theunforgiven
Re: Need little help listing from smallest to largest
Quote:

Originally Posted by MarkFL2
How about f)? What would you say its value is?

So, given what you have so far, can you now give them in the required order?

edit: I was too slow. (Rofl)

Haha. f) would be 0. It's just a point on the graph. :)
• Dec 12th 2012, 10:32 PM
MarkFL
Re: Need little help listing from smallest to largest
f) is asking for the derivative, so you need to look at the slope of the curve at that point, which does incidentally look like it is zero.
• Dec 12th 2012, 10:34 PM
theunforgiven
Re: Need little help listing from smallest to largest
Quote:

Originally Posted by MarkFL2
f) is asking for the derivative, so you need to look at the slope of the curve at that point, which does incidentally look like it is zero.

Oh I see. Guess I just got lucky with that one lol.