## BloomLocke367 one year ago Can someone help with domain and range?

1. theopenstudyowl

yes @BloomLocke367

2. BloomLocke367

FINALLY OS IS WORKING FOR ME. sorry for the delay

3. BloomLocke367

|dw:1441325347989:dw|

4. BloomLocke367

that's just a rough sketch @mathmate can you help? I'm not sure because of the gap

5. BloomLocke367

@phi

6. anonymous

Domain is the interval of defined values in the x axis. (That means they are not undefined.) Range is the interval of defined values in the y axis

7. BloomLocke367

I know what domain and range are xp

8. BloomLocke367

I have a test tomorrow and I'm doing a review sheet lol. I have half of it done xp

9. mathmate

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10. BloomLocke367

yes I know something like that XD

11. BloomLocke367

but it's this particular graph that is bugging me

12. anonymous

I'll help someone then. Pm me if you need further help.

13. mathmate

|dw:1441325830620:dw| Knowing the interval notation also helps. http://www.coolmath.com/algebra/07-solving-inequalities/03-interval-notation-01

14. BloomLocke367

I know how to write interval notation and using inequalities lol XD

15. mathmate

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16. BloomLocke367

wouldn't it be [2,5)?

17. mathmate

|dw:1441326076275:dw| Correction: $$[2,5)\cup(9,\infty)$$

18. mathmate

So it's all clear how you would approach your particular problem?

19. BloomLocke367

yes I know...so would the domain be [-5,-1)U(3,+inf)?

20. mathmate

The 3 in incorrect. The point lies on the y-axis, so it's zero. 3 is the y-coordinate.

21. BloomLocke367

ooopppppppppsss. 0, I just realized that. sorry my sister was talking to me and I really can't focus

22. mathmate

Note: all points on the y-axis have x-value=0.

23. mathmate

Good, so you're all set!

24. mathmate

Can't do the range, because there is not enough information.

25. BloomLocke367

yes I know XD I'm just frustrated. now how would I write that particular domain using equalities?

26. BloomLocke367

INequalities*** ugh

27. mathmate

In set notation, you could write: $$\{x | -5\le x < -1 \cup 0<x<\infty\}$$

28. anonymous

It is possible for the range is the parabola vertex is actually at 3

29. anonymous

if the parabola*

30. BloomLocke367

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31. phi

the "little end" of < is next to the smaller value and the "fat end" is next to the bigger number if you want to say [2,5) you write $2 \le x \lt 5$

32. mathmate

Do you mean (-3,2) ?

33. BloomLocke367

there I fixed that issue. *takes a deep breath* and I know @phi I just didn't know know if U was included or not

34. BloomLocke367

and yes I do omg I just can't get ANYTHING right today. I'm so sorry :(

35. phi

you use U if you have to glue together "separated" domains

36. mathmate

So what do you propose for the range?

37. mathmate

It's similar to the domain, but look along the y-axis.

38. phi

it looks like [0,2] U (3,inf)

39. BloomLocke367

that's what I was about to say @phi. I had to refresh

40. anonymous

Is that an endpoint at the right side of the graph?

41. BloomLocke367

and no, it's an arrow

42. BloomLocke367

so set notation would be {$${y~|~0\le y \le 2 U 3<y<\inf}$$}

43. BloomLocke367

right? or am I wrong? idek. I'm about to give up and go to bed

44. phi

yes

45. BloomLocke367

thank you.