Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

musicdramalife00

  • one year ago

write each polar equation in rectangular form: r=-3sec(Theta) r=costheta+sintheta r=5/3costheta+8sin

  • This Question is Closed
  1. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ^theta after the last sin

  2. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    You need to use these equations: \[r^2=x^2+y^2 ; rcos(\theta)=x ; rsin(\theta)=y \]

  3. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i did, but like it ended up like x^2+y^2= 25+9x^2r^2-30xr/64y^2 for the last one

  4. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    We want the equations just in terms of x and y instead of r and theta.

  5. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i don't know what i did wrong

  6. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    so the last one is: \[r=\frac{5}{3}\cos(\theta)+8\sin(\theta) \]?

  7. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    no uh (5)/(3costheta+8sintheta)

  8. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    oh so you meant 5/(3costheta)+8sin(theta)) and not 5/3cos(theta)+8sin(theta)

  9. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    mhm 5 / (3cos+8sin)

  10. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[r= \frac{5}{3\cos(\theta)+8\sin(\theta)}\] Multiply both sides by that one fraction's denominator

  11. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[r(3\cos(\theta)+8\sin(\theta))=5 \] Distribute then substitute the equations I gave you

  12. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    3xr+8ry=5 but then you'll need to put r on one side cause you would need to square it. and the answer comes out all weird

  13. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    well rcos(theta) is x not just cos(theta same thing with the y deal rsin(theta) is y not just sin(theta)

  14. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    whoops how about the secant one

  15. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    put it in terms of cos by using an identity

  16. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    then put it in some form where you can use the equations I gave you

  17. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sosoososososo it would be x^3+y^2x=-3 AND uh the other one x^2+y^2=x+y?

  18. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    for the first one? no...

  19. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I haven't looked at the second one... You are making this way too hard it looks like.

  20. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    first one you did this as first step right?: \[r=\frac{-3}{\cos(\theta)}\]

  21. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yep

  22. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Notice this only has a cos in it... how do you get cos with the r over there so you can use the equation rcos(theta)=x

  23. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    multiply both sides with r

  24. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    no

  25. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    try again

  26. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    How do you undo multiplication?

  27. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Or division?

  28. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh omg

  29. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    we have division by cos to undo that you ?

  30. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    x=-3

  31. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yes

  32. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    thanks

  33. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    so for that second one...

  34. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    you actually got it right

  35. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    but how did you go about it you didn't choose a complicated way right?

  36. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yep uh multiplied both side with r and then substituted the stuff in

  37. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    oh good

  38. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    do you have any other questions? do you think you got this better?

  39. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    uh yea i have a few more

  40. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    for standard forms of polar equation uh how would graph r=2cos3theta

  41. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Plug in values of theta and see what the r output is

  42. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    then remember how you graph using polar coordinates r is the distance from the origin and direction is given by r to from the angle theta is the angle

  43. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    like how would you do this with a graphing calculator

  44. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    So for example if I plug in theta=0 \[r=2 \cos (3 \cdot 0)=2\cos(0)=2(1)=2 => \text{ graph the point } (2,0^o)\] |dw:1388269865874:dw|

  45. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    find 0 degrees and then go to the circle with radius 2

  46. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    cause wksht says not to use a table

  47. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1388269927627:dw| then plug in more points

  48. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh i know how to graph but not without plugging in points

  49. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    I haven't looked at a calculator in ages

  50. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    did you try looking up how to input polar equations into whatever calculator type you have

  51. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    some calculators require a difference procedure in order to do certain things

  52. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    http://mathbits.com/MathBits/TISection/PreCalculus/polargraphs.htm

  53. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    find mode and choose polar or pol or polargc

  54. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    then just type your equation in

  55. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    u what's the website

  56. musicdramalife00
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    *uh

  57. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    What ?

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

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

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.