sktjell 3 years ago The reciprocal function f(x)=1/x satisfies which of the following statements? Check all that apply.. A. It exhibits inverse variation. B. Its range is all real numbers. C. It exhibits direct variation. D. Its domain is all real numbers except for zero.

1. imagreencat

Go to the choices one by one. Do you think A is correct?

2. sktjell

I dont understand what any of them mean, so i couldnt tell you, im really slow in math, :'(

3. experimentX

Jeez .... you are trying to tackle question without knowing what there terms are??

4. sktjell

i just dont understand and i have so much to do! IM SO SORRY :(

5. experimentX

first search what what are direct variations and inverse variations ...

6. sktjell

ok

7. experimentX
8. sktjell

In an inverse variation, the values of the two variables change in an opposite manner - as one value increases, the other decreases.

9. sktjell

can u dumb that down for me ... :/

10. sktjell

@experimentX Im a senior i just finished school and 50 assigments with questions like these in them before june 3rd or i cant walk with my class on june 6th, This because i failed ceramics by 2 points because the teacher hatted me and gave me a failing grade, they then put me in a math class online like im doing now to help me fill in the half a credit i need to graduate so im begging you please give me the answer, i learned all this when i was a freshman but i havent done it in a while i have so much to do in so little time and re learning things is just not ganna help PLEASE :(

11. experimentX

I suggest you focus on learning ... what will you do with answers if you don't know that they mean?

12. experimentX

finish that video ... i'll give you half answer

13. sktjell

omg :'( this only question 4 of this stupid thing ive been on here for hours, and im only on question 4! ill never get this done in a week. (Sigh) i appreciate your help, but im sorry, watching a 9 minute video does not help me with time, i need to finish this fast. Thanks i really appreciate it though u also helped me on other questions which i do appreciate. I REALLY DO.

14. imagreencat

Well, it says that inverse variation involves two quantities wherein as the other one increases, the other decreases. Take for example: 8 workers paint a house for 5 days; 10 workers paint the house for 2 days. Since there are more workers, the work could be done in a shorter time. That's inverse variation. Do you somehow get it?

15. sktjell

okay yea.

16. experimentX

so what do you think ??? does f(x) increase or decrease with x??

17. sktjell

increase?

18. experimentX

f(1) = 1/1 = 1 f(10) = 1/10 = 0.1 do you think it is increasing

19. imagreencat

Well, with the denominator increasing, what do you think will happen to the quotient of 1 and the increasing denominator?

20. imagreencat

Just think of it this way, the number 1 is divided into greater and greater parts. So great that it will reach infinity! Do you now think it is still increasing?

21. sktjell

ooh no its decreasing

22. sktjell

its breaking up into smaller numbers to make a bigger number

23. experimentX

well ... this is called inverse variation!!

24. sktjell

okay so is that it?

25. experimentX

half part

26. imagreencat

Yes, well A is correct. Go check the other ones. Tell us what you think of each option.

27. experimentX

since it's inverse variation ... it cannot be direct variation now two option left

28. sktjell

i think b is right

29. experimentX

don't make guess ... i'm not gonna answer

30. experimentX

first search for what's "real number"

31. sktjell

B IS RIGHT BECAUSE IT DOES HAVE REAL NUMBERS DOSENT IT

32. sktjell

i know what real numbers are, they are every number basically

33. experimentX

is pi a real number??

34. experimentX

is 1 and 10 real number??

35. sktjell

yes

36. experimentX

*are ...

37. experimentX

is 0 real number??

38. sktjell

yes

39. experimentX

find f(x) at 0

40. sktjell

its not there

41. imagreencat

Why is it not there?

42. imagreencat

Because..

43. sktjell

listen guys i appreciate you guys tring to teach me but again, this is question 4 and weve been doing this for about 20 minutes now. i still have 6 more questions to do and then after that i have 50 more quizes like this to do in 7 days. so ill just guess and fail like i did before but i really apprciate you guys helping me with the last answer.

44. experimentX

ah ... i misread ... i thought it was domain

45. sktjell

honestly i would have sat there and learned it but i just dont have the time

46. experimentX

okay ... the range is all over the real numbers now we have only one statement

47. sktjell

I GUESSED A B AND D THANKS GUYS.

48. imagreencat

The range can't be zero. So the range is not all real numbers.

49. experimentX

i'm still not sure if you can consider infinity to be real numbers or not generally ... i have said lim x->inf 1/x = 0

50. imagreencat

Well yeah. But as far as I can remember, my calc teacher told me that infinity is not a number. That's why you can't close bracket the infinity sign. :)

51. experimentX

I guess you are right http://en.wikipedia.org/wiki/Extended_real_number_line there's been a long debate on infinity ... observing it only made me confused still ... lim x-> inf ... will never make 0 on range

52. experimentX