Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

lilsis76 Group Title

11.2 the Parabola. Its says Conic sections: suppose PQ is a focal chord of the parabola y=x^2 and that the coordinates of P are (2,4) a)find coordinate of Q b)find coordinates of M, the midpoint of PQ. c) A perpendicular is drawn from M to the y axis, meeting the y axis at S. Also, a line perpendicular to the focal chord is drawn through M, meeting the yaxis and T. Find ST, and verify its equal to one-half the focal width of the parabola.

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1352584620353:dw|

    • 2 years ago
  2. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1352584696851:dw|

    • 2 years ago
  3. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    whats a focal chord? I was givin this homework problem and instructor confused me on all the different positions

    • 2 years ago
  4. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Any chord to y2 = 4ax which passes through the focus is called a focal chord of the parabola y2 = 4ax.

    • 2 years ago
  5. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    @lilsis76 tell me the focus of ur parabola?????:)

    • 2 years ago
  6. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    well, it didnt give me a focus it just gave me the P at (2,4)

    • 2 years ago
  7. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    it also says the parabola is y=x^2 so...um the p, 1/4

    • 2 years ago
  8. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    @lilsis76 focus of x2 = 4ay is(0,a) so compare it with x^2=y this implies 4a=1 or a=1/4 so it is(0,1/4).k

    • 2 years ago
  9. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    okay im back!

    • 2 years ago
  10. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    now you have 2 points p(2,4) and focus f(0,1/4) so can u draw a line???????????

    • 2 years ago
  11. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yes i can

    • 2 years ago
  12. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1352585497197:dw|

    • 2 years ago
  13. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    so thats ur focal chord any chord passing through focus is called focal chord:)

    • 2 years ago
  14. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    let me write that down

    • 2 years ago
  15. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    did i make the line right?

    • 2 years ago
  16. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    ya you make it right:) sry i didn't noticed ur reply:( @lilsis76

    • 2 years ago
  17. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    haha its okay. but thank u for letting me know. Okay whats next what do i have to do?

    • 2 years ago
  18. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1352586259141:dw| now what is the coordinate of any point on parabola?????

    • 2 years ago
  19. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    wait, its a normal looking parabola with the point (0,0) right? thats how you got that parabolas shape?

    • 2 years ago
  20. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    im sorry im kinda new to this lol

    • 2 years ago
  21. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    since you said any point. ill go to the left. the Q would be P's opposite and be .. -2,4? right?

    • 2 years ago
  22. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    well it is not what i asked i asked general form it is(x,x^2) :) as PFQ is a straight line so slope of PF=FQ now find their slopes...........when u solve this completely i will tell you a short method:)

    • 2 years ago
  23. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    @lilsis76

    • 2 years ago
  24. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    okay. im trying to do PF, is that ...getting the 2*1/4?

    • 2 years ago
  25. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    PF??????????

    • 2 years ago
  26. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    hmm... let me try again

    • 2 years ago
  27. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    1/4th?

    • 2 years ago
  28. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    WAIT let me try again

    • 2 years ago
  29. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    i got..... 4 - 1/4 / 2-0

    • 2 years ago
  30. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1352587321957:dw| i dont know how to work out the fraction and whole number

    • 2 years ago
  31. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    slope m=|dw:1352587256238:dw| solve for x i just compare the two slopes:)

    • 2 years ago
  32. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    15/4/2--> 15/8

    • 2 years ago
  33. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    @Aperogalics

    • 2 years ago
  34. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    @lilsis76 is it value of x?????????

    • 2 years ago
  35. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yes? how do i know?

    • 2 years ago
  36. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    i have to solve:(

    • 2 years ago
  37. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    oh. well then imma say yes it is then

    • 2 years ago
  38. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1352587871193:dw|

    • 2 years ago
  39. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    how did you get the 13/8?

    • 2 years ago
  40. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1352588075547:dw| so x=-1/8 or 2

    • 2 years ago
  41. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    haha okay. thanks

    • 2 years ago
  42. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    ugh factoring

    • 2 years ago
  43. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    coordinates are (x,x^2) from fig x<0 x cannot be =2 Q=(-1/8,1/16)

    • 2 years ago
  44. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    okay i got the -1/8

    • 2 years ago
  45. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    and the 2, did you just add the 1/8 th twice to get 1/16?

    • 2 years ago
  46. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    now shortcut method:) Let y2 = 4ax be the equation of a parabola and (at^2, 2at) a point P on it. Suppose the coordinates of the other extremity Q of the focal chord through P are (at1^2, 2at1). then t1=-1/t:) so |dw:1352588333605:dw|

    • 2 years ago
  47. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    no @lilsis76 as the coordinates are(x,x^2)

    • 2 years ago
  48. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    @lilsis76 did u got it?????????

    • 2 years ago
  49. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    kinda, not really. okay well i ended up getting the - 1/8 for x, i plug it in right?

    • 2 years ago
  50. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yup:)

    • 2 years ago
  51. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    ok i got 8x+1 an x-2, x= -1/8, x=2

    • 2 years ago
  52. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    now go ahead for shortcut:)

    • 2 years ago
  53. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    the shortcut u gave me?

    • 2 years ago
  54. Aperogalics Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yup:)

    • 2 years ago
  55. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    i got -1/8

    • 2 years ago
  56. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    @Aperogalics

    • 2 years ago
  57. lilsis76 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    anywho, i did the math cuz shortcut got me lost. i have x = -1/8 and x=2

    • 2 years ago
    • Attachments:

See more questions >>>

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.