[College - Calculus III] Vectors and Planes

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  • argo15
    FFR Veteran
    • May 2006
    • 1863

    #1

    [College - Calculus III] Vectors and Planes

    Gosh, it might be a brain fart but I can't figure out how to do this.

    Code:
    Find a vector equation and parametric equations in t for the line through the point and perpendicular to the given plane. (P0 corresponds to t = 0.)
    P0 = (4, 0, 7)
    x + 2y + z = 6
    v = ?i + ?j + ?k
    x = ?
    y = ?
    z = ?
    Answers or anything that might send me in the right direction would be awesome. =)
  • JKPolk
    tool
    • Aug 2003
    • 3737

    #2
    Re: [College - Calculus III] Vectors and Planes

    Have you tried taking the derivative with respect to each of the values and plugging in the intial conditions?

    Comment

    • argo15
      FFR Veteran
      • May 2006
      • 1863

      #3
      Re: [College - Calculus III] Vectors and Planes

      I don't think that is what he is looking for since this assignment is in the chapter before derivatives of vectors. Dot products or cross products are probably involved.

      Comment

      • dooty_7
        FFR Player
        • Jun 2005
        • 462

        #4
        Re: [College - Calculus III] Vectors and Planes

        I haven't done this for a while, so I hope what I say is not complete gibberish lol

        For the equation of a plane, aren't the coefficients simply the normal (perpendicular) to the plane? If so then we have P0 = 4,0,7 and normal 1,2,2.

        Leading us to get the general equation r = (4,0,7) + t(1,2,2)
        so x = 4 + t
        y = 2t
        z = 7 + 2t

        Comment

        • foilman8805
          smoke wheat hail satin
          FFR Simfile Author
          • Sep 2006
          • 5704

          #5
          Re: [College - Calculus III] Vectors and Planes

          Originally posted by dooty_7
          I haven't done this for a while, so I hope what I say is not complete gibberish lol

          For the equation of a plane, aren't the coefficients simply the normal (perpendicular) to the plane? If so then we have P0 = 4,0,7 and normal 1,2,2.

          Leading us to get the general equation r = (4,0,7) + t(1,2,2)
          so x = 4 + t
          y = 2t
          z = 7 + 2t
          Normal for the given plane is 1, 2, 1. I know it's a mistake though. You didn't mean to do that on purpose.

          As a result the parametrics change to:

          x = 4 + t
          y = 2t
          z = 7 + t

          So, v is going to then be a substitution of the parametrics back into i, j, k form? I don't remember either lol...

          EDIT: Yeah, I think v = (4 + t)i + (2t)j + (7 + t)k
          Last edited by foilman8805; 09-29-2009, 01:10 PM.

          Comment

          • argo15
            FFR Veteran
            • May 2006
            • 1863

            #6
            Re: [College - Calculus III] Vectors and Planes

            Yeah, your right thank you =).

            Answer was v= (4+t)i + (2t)j + (7+t)k

            If I have any more issues I'll edit it in here. (math can be a bitch sometimes)

            Comment

            • foilman8805
              smoke wheat hail satin
              FFR Simfile Author
              • Sep 2006
              • 5704

              #7
              Re: [College - Calculus III] Vectors and Planes

              If you have more issues, bump the thread, otherwise we probably won't come back to look for it.

              Comment

              • dooty_7
                FFR Player
                • Jun 2005
                • 462

                #8
                Re: [College - Calculus III] Vectors and Planes

                lol brain fart on my part haha :P

                Comment

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