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Homework Help: Cylindrical coordinate convertion

  1. Jun 29, 2010 #1
    1. The problem statement, all variables and given/known data
    cylindrical coordinates: r=2cscƟ, give both rectangular and spherical cordinates



    2. Relevant equations
    I know this:
    From rectangular to cylinder
    z=z r2=x2+y2 tanƟ=y/x
    From Cyl to rectangle
    x=cosƟ y=sinƟ z=z
    From cyl to spherical
    Ɵ=Ɵ ρ2=x2+y2+z2 ɸ=sin-1r/ρ
    From Spherical to cylindrical
    Ɵ=Ɵ r=ρsinɸ z=ρcosɸ



    3. The attempt at a solution
    so far what I have is
    r=2/sinƟ



    can anyone please help me, I got stuck
     
  2. jcsd
  3. Jun 29, 2010 #2

    Mark44

    Staff: Mentor

    So r sinƟ = 2
     
  4. Jun 29, 2010 #3
    yes but I need to find
    x
    y
    z
    r
    Ɵ
    ρ
    ɸ
     
  5. Jun 29, 2010 #4

    Mark44

    Staff: Mentor

    What does the equation r sinƟ = 2 represent geometrically?
     
  6. Jun 29, 2010 #5
    im not sure, what i know is that 1/sinƟ = cscƟ. and since in the conversions i have "sin"
    thats why I replaced r=2cscƟ with r=2/sinƟ
    someone elso solved for 2 and got rsinƟ=2
     
  7. Jun 29, 2010 #6
    im not sure, what i know is that 1/sinƟ = cscƟ. and since in the conversions i have "sin"
    thats why I replaced r=2cscƟ with r=2/sinƟ
    someone else solved for 2 and got rsinƟ=2
     
  8. Jun 29, 2010 #7

    Mark44

    Staff: Mentor

    What can you replace rsinƟ with? BTW your conversion formulas from cylindrical to rectangular are wrong.
     
  9. Jun 29, 2010 #8
    ok
    x=rcosƟ y=rsinƟ
     
  10. Jun 29, 2010 #9
    y=2
    ok, i'm getting somewhere
     
    Last edited: Jun 29, 2010
  11. Jun 29, 2010 #10

    Mark44

    Staff: Mentor

    Yes, you have now partially answered my question in post 4. What does y = 2 represent geometrically?
     
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