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Homework Help: Calc 3 question (binormal, normal vectors)

  1. Mar 4, 2009 #1
    Hi, this is a calc 3 question. I know the binormal is given by

    B = T x N

    where
    Binormal vector, B
    Tangent vector, T
    Normal vector, N

    Also,
    B = (R'(t) x R''(t)) / | R'(t) x R''(t) |
    T = R'(t) / | R'(t) |

    Does that mean
    N = R''(t) / |R''(t)|?
     
    Last edited: Mar 4, 2009
  2. jcsd
  3. Mar 4, 2009 #2

    HallsofIvy

    User Avatar
    Science Advisor

    No.
    [tex]\vec{N}= \frac{\vec{T}'}{|\vec{T}'|}[/itex]
    Which is NOT the same as
    R"/|R"|
    if |T| is not a constant.
     
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