A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Babynini

  • one year ago

Find two polar coordinate representations for the rectangular coordinate point (-6, 2 (sqroot3)), one with r>0, one with r<0 and both with <thetha<2pi

  • This Question is Closed
  1. Babynini
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    For r I already got 4 (sqroot3) and -4 (Sqroot3)

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

    and then tan(theta)= -(2(sqroot3))/6

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

    @rvc :) I know you just got on. But if you're free!

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

    ah bit busy dear :( @JoannaBlackwelder

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

    \[\tan(\theta) = -\frac{ 2\sqrt{3} }{ 6 }\]

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

    The tan equation looks good to me :-) Can you solve for theta?

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

    em theta = arctan (x) but i'm not sure how to keep it not in decimal form

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

    ....?

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

    We will need to use the unit circle and the idea that tan is sin/cos

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

    http://www.mathsisfun.com/geometry/unit-circle.html Look down at the very bottom chart.

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

    I'm not finding anywhere that tangent equals that on the unit circle. It is sq3/3 at pi/6

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

    and -sq3/3 at 11pi/6

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

    Right, and -2sqrt3/6 is -sqrt3/3

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

    oh.. We can take the 6 and divide it by the 2 in the numerator?

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

    Yep, those can simplify, since they have a common factor of 2

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

    Do you see another one other than 11pi/6?

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

    5pi/6

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

    so how do I know which to choose? 11pi/6 or 5pi/6 ?

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

    Awesome! We are looking for 2 options, so both.

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

    And I don't get what you got for r. How did you get that?

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

    Give me a moment to type that up :)

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

    Oh, sorry, my mistake. You're rs are correct! :-)

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

    As long as you can combine them correctly.

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

    Into two pairs.

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

    \[r^2=x^2+y^2\] \[r^2=-6^2+(2\sqrt{3})^2\] \[r^2=36+12 = \sqrt{48}\] Simplify and get \[r=4\sqrt{3}\]

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

    Right, how do I know how to pair them?

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

    (4 sq3, 5pi/6) (-4 sq3, 11pi/6) right? but i'm not sure how I got there xD or why

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

    Let's look at each of those graphically to see if they look like they are in the right spots.

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

    |dw:1434646002351:dw|

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

    Here is a rough graph of the rectangular coordinate.

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

    |dw:1434646256752:dw|

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

    Yeah?

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

    Yep, great!

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

    Fantastic, thanks :)

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

    No worries :-)

  36. 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.