A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

cutiecomittee123

  • one year ago

how do i find the foci of an elipse?

  • This Question is Closed
  1. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    do you know where the center and vertexes are?

  2. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    if so, then the foci are an odd construction of the usual pythag thrm ... in this case, b and c are legs, and a is a hypotenus giving us a rather strange look of c^2 + b^2 = a^2, such that x is the distance from center to focus

  3. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    well the equation i have is (x+2)^2/9+(y-4)^2/36=1

  4. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    then we know a^2 and b^2, right?

  5. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

  6. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so show me c^2 :)

  7. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    36+ =9 c^2=25

  8. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    -25

  9. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    36 - 9 = 27

  10. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh yeah lol

  11. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so 3cbrt3 = c, or this distance from center.

  12. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    3 sqrt3 lol

  13. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    so, tell me our center, and in what direction we need to move

  14. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    center (-2,4) we move left and right

  15. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    not left and right notice that under y is bigger than under x y is bigger than x, so our focuses are going to be in relation to y |dw:1433524715502:dw|

  16. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so (-2, 4+ or - 3sqrt3)

  17. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    yes

  18. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    alright

  19. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thanks:)

  20. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    youre welcome

  21. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    can you help me with one other thing

  22. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    depends on what it is and how good my memory is :)

  23. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    finding the eccentricity of (x+7)^/16+(y-3)^2/4=1

  24. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    define the formula for eccentricity

  25. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    eccentricity = c/a

  26. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    thats what i thought so sqrt(c^2/a^2) should work .. c^2 is the difference of the bottoms, and a^2 is the larger of them

  27. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So sqrt 12/4

  28. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    um, 16 is bigger than 4

  29. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    because sqrt 16 is 4

  30. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    oh, youve got some notation off then sqrt(12/16) sqrt(3/4) sqrt(3)/2

  31. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Wait I dont get how you reduced those? wouldnt it just be sqrt(3/4)

  32. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Like why did you reduce so far?

  33. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    thats what you do with fractions, you reduce them till they have no common factors

  34. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    makes sense.

  35. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So final answer is sqrt (3/2)

  36. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    \[\sqrt{\frac{16-4}{16}}\] \[\sqrt{\frac{12}{16}}\] \[\sqrt{\frac{4*3}{4*4}}\] \[\sqrt{\frac{3}{4}}\] \[\frac{\sqrt3}{\sqrt4}\]

  37. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    then reduce? or

  38. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    can it be simplified more?

  39. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    i just showed you some of the process, i didnt finish it ... i figured youd be cognizant enough to see where its going.

  40. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yea sqr t4 is equal to 2

  41. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    then lets go with sqrt(3) /2

  42. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Then you have sqrt(3/2) :) thanks

  43. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    no, not sqrt (3/2) im not sure if its a typing error of yours, or if you are making a mistake. it is: sqrt(3) ------ 2

  44. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    sqrt(3) sqrt(3) ----- = ----- sqrt(4) 2

  45. cutiecomittee123
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah thats how I percieved it and meant it

  46. amistre64
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 2

    good luck :)

  47. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

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.