## anonymous 3 years ago Find the x-intercepts: 2(x-5)^2=17

1. anonymous

x= [17/2]^1/2 +5|dw:1345790422320:dw|

2. anonymous

x-intercepts? this is an equation in one variable.... how do you do that?

3. anonymous
4. anonymous

Am I suppose to distribute the 2?

5. anonymous

ahh.... my bad.... because this is an equation in one variable, it is just a vertical line.... so solving for x will give you the only x-intercept....

6. anonymous

since this is a quadratic function, you will get 2 values for the x-intercepts. read pp 126-129 in the link I've posted above.

7. anonymous

2 x-intercepts? $2(x-5)^2=17$Divide both sides by 2$(x-5)^2=\frac{17}{2}$Take square roots for both sides $(x-5)=\pm \frac{17}{2}$Add 5 to both sides to get the answer.

8. anonymous

I'm always late....

9. anonymous

oh okay thank you that makes so much sense :)

10. anonymous

hold on folks... this is an equation in x only.... this is a vertical line.... and not a function.... "Find the x-intercepts: 2(x-5)^2=17"

11. anonymous

Wow. That's complicated. I thought all I had to do was to solve it but seems not :(

12. anonymous

this is a function: y = 2(x-5)^2 this is not a function: 17 = 2(x-5)^2

13. anonymous

parabolas always have 2 x-intercepts unless k=0, is it not?

14. anonymous

But how to get the x-intercept(s)??? There is no y...

15. anonymous

in any function, to find the x-intercepts, set y=0 and solve.... how are you gonna set y=0 in the equation 2(x-5)^2 =17 ????

16. razor99

Think the x-intercept is 8.5,0

17. anonymous

Perhaps this would be the case? y = 2(x-5)^2-17 Put y=0 2(x-5)^2-17 = 0 2(x-5)^2=17 . . . Solve x to find the x-intercepts. Hmm...

18. anonymous

dpalnc solved it, x=5 - sqrt(17/2) x=5+ sqrt(17/2)

19. anonymous

compare these two equations: y = x + 3 and 17 = x + 3 that first one is a line and you can find the x-intercept by setting y=0 then solving 0 = x + 3. but that second equation is just a vertical line....

20. anonymous

Eh?! Then, for 17=x+3, the x-intercept is 17-3 = 14?!

21. anonymous

you have been trolled

22. anonymous

dang this chrome browser.... x = 14 is a vertical line and that's where it crosses the x-axis.... but back to the problem... did i say 1 x-intercept? i mean two as panlac says.... :)

23. anonymous

LOL

24. anonymous

a vertical line that curves...obviously troll ^^

25. anonymous

how 'bout two vertical lines... it's implied when u solve a quadratic you have to consider the positive and negative square root....

26. anonymous

^trOWL

27. anonymous

yeah buwahhahahahaha

28. anonymous

ang troll ^^^

29. anonymous

this goes against the teachings of the monks... the forefathers defined x-intercept as "the value of y when x is 0" however, there is no y....

30. anonymous

this is not a function

31. anonymous

right... so when you solve for x in that equation, you get two vertical lines... an equation in only 1 variable x is not a function...

32. anonymous

no. this is just not a function. nothing more; nothing less

33. anonymous

it's a relation, but not a function

34. anonymous

x-intercepts occur in function only

35. anonymous

when did i say it is a function?

36. anonymous

I said it was, my mistake

37. anonymous

you were saying it had an x-intercept

38. anonymous

two values for x...

39. anonymous

it has values for x...but no x-intercept

40. anonymous

but the vertical line intercepts the x-axis...

41. anonymous

yes. LG you are right

42. anonymous

http://mathworld.wolfram.com/x-Intercept.html "The point at which a curve or FUNCTION crosses the x-axis (i.e., when in two dimensions)."

43. anonymous

like i said. you got trolled

44. anonymous

cross or touches...

45. anonymous

so are you saying that a circle (which is a curve) does not have x-intercepts?

46. anonymous

yes it doesnt. it's not a function

47. anonymous

circle is not a function

48. anonymous

neither do ellipses

49. anonymous

function = 1 to 1 value

50. anonymous

so why can't you call the where a vertical line crosses the the x-axis the x-intercept?

51. anonymous

any closed figure is not a function. it is a plane

52. anonymous

this is going beyond the problem now... bottom line: x has two values

53. anonymous

i agree to agree... if that makes sense....

54. anonymous

hey LG... i thnk u scared off the asker.... or he/she got bored...

55. anonymous

did she ask the problem to be graphed?

56. anonymous

lol jk. let us just leave it

57. anonymous

i would like to quote myself "you got trolled" relations have x-intercepts too http://en.wikibooks.org/wiki/Algebra/Intercepts

58. anonymous

yes.... let's graph it....

59. anonymous

this is really going beyond now... why can't we agree that the intercepts are where either the vertical line or horizontal line are touched or crossed? did I start the fire when I said it was a function? I retracted it so OS can be a better place for students once again...

60. anonymous

sorry man... i just miss talkin to LG....

61. anonymous

u know u'd make a great ambassador for keeping the peace....:)

62. anonymous

so peace to everyone.....:)

63. anonymous

I'd be damned...

64. anonymous

lol...