domain and range

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zevenzeros

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Been trying to figure out how to even start this problem. If anyone could give me the answer, a how to do it and if you have a video or good place to read up on how to do this. Thanks for any help.
 

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The range of f will be the set of all b such that f(a)=b for all a in the domain of f. I hope this will help you.
 
Definitions are always a good place to start! yoscar04 has given you the definition of "domain"- the domain of a function, f, is the set of all value of x such that f(x) exist, that there is some y such that y= f(x).

Similarly, the "range" of a function, f, is the set of all values of y such that there is some x such that y= f(x). Since the graph of a function is the set of all points (x, f(x)), the domain of this function is the set of all values of x (on the horizontal axis) such that there is a point on the graph directly above or below that x-point on the axis. And the range is the set of all values of y (on the vertical axis) such that there is a point on the graph directly to the right or left of the that point on the axis.

I have to say, however, that it appears that none of the given "answers" are correct!
 
HallsofIvy said:
Definitions are always a good place to start! yoscar04 has given you the definition of "domain"- the domain of a function, f, is the set of all value of x such that f(x) exist, that there is some y such that y= f(x).

Similarly, the "range" of a function, f, is the set of all values of y such that there is some x such that y= f(x). Since the graph of a function is the set of all points (x, f(x)), the domain of this function is the set of all values of x (on the horizontal axis) such that there is a point on the graph directly above or below that x-point on the axis. And the range is the set of all values of y (on the vertical axis) such that there is a point on the graph directly to the right or left of the that point on the axis.

I have to say, however, that it appears that none of the given "answers" are correct!
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I also noticed that the correct answer was not among the 4 answers. Maybe there is a fifth one?
 
yoscar04 said:
Really weird that they include the tip of the arrows both ways, right, left and up, down.
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Hi. That's common, yoscar, in beginning courses that I've seen. Instructors have told me that such labels emphasize the axes as Real number lines or indicate only a portion of the xy-plane shown. Personally, I prefer one arrow per axis -- pointing toward the positive direction (whatever that may be).

Regarding the given exercise: We have to assume what the graph looks like in QIII, we have to assume the vertical and horizontal units, and none of the choices can be correct (with any set of assumptions). What a mess!

:rolleyes:
 
Im reading that infinity can only be placed in ( ) and not [ ] making B and D the only possible answers. This is about as far as i have gotten on this. Unless its the fact that all answers are wrong and need to email a teacher to check this.
 
zevenzeros said:
Im reading that infinity can only be placed in ( ) and not [ ] making B and D the only possible answers. This is about as far as i have gotten on this. Unless its the fact that all answers are wrong and need to email a teacher to check this.
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The range is the set (-[MATH]\infty[/MATH],-1].
The domain is the set (-[MATH]\infty[/MATH],3)
 
Just got off the phone with the math teacher confirmed no answer is correct because the infinity should be negitive. Correct answer should be B with negative infinity in the range.thanks everyone for the help.
 
zevenzeros said:
Just got off the phone with the math teacher confirmed no answer is correct because the infinity should be negitive. Correct answer should be B with negative infinity in the range.thanks everyone for the help.
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Nice. Thanks for the update. The most important thing is that you learned how to answer this kind of questions.
 
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