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Homework Help: Please help me find a basic plane equation

  1. Jan 20, 2010 #1
    Q: Find an equation of a plane through the point (3, -3, -2) which is parallel to the plane −2x+1y+4z=−6 in which the coefficient of x is -2.

    The website asks you to format the answer equal to zero. My input is -2x+y+4z+23, but it shows wrong. I have checked my answer a couple of times, but am not sure how to approach it differently.
     
  2. jcsd
  3. Jan 20, 2010 #2

    tiny-tim

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    Welcome to PF!

    Hi krtica! Welcome to PF! :smile:

    That doesn't go through (3, -3, -2). :wink:
     
  4. Jan 20, 2010 #3
    Re: Welcome to PF!

    Thanks!

    Isn't the equation for a plane a(x-xi)+b(y-yi)+c(z-zi)=0? Where a,b,c are the vector components?
     
  5. Jan 20, 2010 #4

    tiny-tim

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    Yes, but if you have actual numbers, it's a lot easier to write it as ax + by + cz = …, and just fill in the number so that it fits the given point. :wink:
     
  6. Jan 20, 2010 #5
    By filling in the numbers, do you mean substituting the point in x,y,z? I am not quite sure exactly what you mean, my apologies.
     
  7. Jan 20, 2010 #6

    tiny-tim

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    Yes, substituting the point in ax + by + cz …

    then it's bound to go through that point, isn't it? :wink:
     
  8. Jan 20, 2010 #7
    God! Got it.

    Thank you, I really do appreciate your help.
     
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