## AudrianaS Group Title Find the x-intercepts: 2(x-5)^2=17 2 years ago 2 years ago

1. manishsatywali Group Title

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

2. dpaInc Group Title

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

3. panlac01 Group Title
4. AudrianaS Group Title

Am I suppose to distribute the 2?

5. dpaInc Group Title

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. panlac01 Group Title

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. RolyPoly Group Title

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. RolyPoly Group Title

I'm always late....

9. AudrianaS Group Title

oh okay thank you that makes so much sense :)

10. dpaInc Group Title

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. RolyPoly Group Title

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

12. dpaInc Group Title

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

13. panlac01 Group Title

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

14. RolyPoly Group Title

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

15. dpaInc Group Title

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 Group Title

Think the x-intercept is 8.5,0

17. RolyPoly Group Title

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. panlac01 Group Title

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

19. dpaInc Group Title

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. RolyPoly Group Title

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

21. lgbasallote Group Title

you have been trolled

22. dpaInc Group Title

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. panlac01 Group Title

LOL

24. lgbasallote Group Title

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

25. dpaInc Group Title

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

26. lgbasallote Group Title

^trOWL

27. dpaInc Group Title

yeah buwahhahahahaha

28. dpaInc Group Title

ang troll ^^^

29. lgbasallote Group Title

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. lgbasallote Group Title

this is not a function

31. dpaInc Group Title

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. lgbasallote Group Title

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

33. lgbasallote Group Title

it's a relation, but not a function

34. lgbasallote Group Title

x-intercepts occur in function only

35. dpaInc Group Title

when did i say it is a function?

36. panlac01 Group Title

I said it was, my mistake

37. lgbasallote Group Title

you were saying it had an x-intercept

38. panlac01 Group Title

two values for x...

39. lgbasallote Group Title

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

40. dpaInc Group Title

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

41. panlac01 Group Title

yes. LG you are right

42. lgbasallote Group Title

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. lgbasallote Group Title

like i said. you got trolled

44. panlac01 Group Title

cross or touches...

45. dpaInc Group Title

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

46. lgbasallote Group Title

yes it doesnt. it's not a function

47. panlac01 Group Title

circle is not a function

48. lgbasallote Group Title

neither do ellipses

49. panlac01 Group Title

function = 1 to 1 value

50. dpaInc Group Title

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

51. lgbasallote Group Title

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

52. panlac01 Group Title

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

53. dpaInc Group Title

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

54. dpaInc Group Title

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

55. panlac01 Group Title

did she ask the problem to be graphed?

56. panlac01 Group Title

lol jk. let us just leave it

57. lgbasallote Group Title

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

58. dpaInc Group Title

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

59. panlac01 Group Title

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. dpaInc Group Title

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

61. dpaInc Group Title

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

62. dpaInc Group Title

so peace to everyone.....:)

63. panlac01 Group Title

I'd be damned...

64. dpaInc Group Title

lol...