Domain of graphed functions..

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Dannielle

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I'm sorry I'm asking all of these questions. I'm just really confused and tired. How would I be able to find a domain of a function that is graphed? What IS a domain of a graphed function? This question asks: "What is the domain of the function graphed." Above, it has a graph with a point of (-3, 4) and a slope of -4/5... It doesn't go farther into the 2nd quadrant than the point (-3, 4). The line only goes downward and another point it passes through is (2, 0).

I'm not exactly sure how well I did with describing the graph but I don't know what steps to take to find the domain...?
 
Dannielle said:
I'm sorry I'm asking all of these questions. I'm just really confused and tired. How would I be able to find a domain of a function that is graphed? What IS a domain of a graphed function? This question asks: "What is the domain of the function graphed." Above, it has a graph with a point of (-3, 4) and a slope of -4/5... It doesn't go farther into the 2nd quadrant than the point (-3, 4). The line only goes downward and another point it passes through is (2, 0).

I'm not exactly sure how well I did with describing the graph but I don't know what steps to take to find the domain...?
Click to expand...
Danielle, please look at my most recent answer to your post about the range of a polynomial. See whether that answers your question.
 
JeffM said:
Danielle, please look at my most recent answer to your post about the range of a polynomial. See whether that answers your question.
Click to expand...

Okay... Um.. How do I set it up from the graph to figure this out?
 
Do the endpoints of the line have arrows, solid or empty dots?
 
Dannielle said:
Point (-3, 4) is a solid dot, the other end it an arrow.
Click to expand...

Okay, so the solid dot means that -3 in included in the domain, but nothing less is included.

The arrow at the other end means that the line extends indefinitely in that direction, hence we may conclude that all values for x equal to or greater than -3 are in the domain. Which means \(\displaystyle -3\le x\) or in interval notation \(\displaystyle [-3,\infty)\).
 
Dannielle said:
I'm sorry I'm asking all of these questions. I'm just really confused and tired. How would I be able to find a domain of a function that is graphed? What IS a domain of a graphed function? This question asks: "What is the domain of the function graphed." Above, it has a graph with a point of (-3, 4) and a slope of -4/5... It doesn't go farther into the 2nd quadrant than the point (-3, 4). The line only goes downward and another point it passes through is (2, 0).

I'm not exactly sure how well I did with describing the graph but I don't know what steps to take to find the domain...?
Click to expand...

Some useful web-sites for you to study:

http://www.purplemath.com/modules/fcns2.htm

http://www.coolmath.com/algebra/15-functions/06-finding-the-domain-01.htm

http://www.youtube.com/watch?v=sbvSBH2Mo20

[url]https://www.khanacademy.org/math/algebra/algebra-functions/domain_and_range/v/domain-of-a-function
[/URL]
 
MarkFL said:
Okay, so the solid dot means that -3 in included in the domain, but nothing less is included.

The arrow at the other end means that the line extends indefinitely in that direction, hence we may conclude that all values for x equal to or greater than -3 are in the domain. Which means \(\displaystyle -3\le x\) or in interval notation \(\displaystyle [-3,\infty)\).
Click to expand...

Thank you! I understand now.
 
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