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I forgot what the formula for this is.

  1. Nov 12, 2011 #1
    If I give you a function f(x) (cartesian) and I ask you to rotate it about the x axis (counterclockwise) by an angle phi, what is the new function formula?

    I remember I did this with matrices, but I can't remember the one for functions. For convenience, let angle phi be 0, pi/2, 3pi/2, and 2pi.

    I am guessing 0 would remain the same. I just don't know how to use matrices on functions.

    Does anyone understand my question?
  2. jcsd
  3. Nov 12, 2011 #2
  4. Nov 12, 2011 #3
    There's obviously [itex]SO(n)[/itex] but that's matrices.

    Doesn't Euler's formula do that same thing?

    [itex]e^{i\theta} = cos\theta + isin\theta[/itex]

    EDIT: Euler's formula is only for complex numbers.
  5. Nov 12, 2011 #4
    Yes, but for functions. Is there no equivalence? I kinda had something like this for conics
  6. Nov 12, 2011 #5
    No real numbers please
  7. Nov 12, 2011 #6
    Hhhmmm...if you have a set of points, I can see being rotated with a transformation matrix...but a function? If you have a function f(x) and you "rotate" it 90 degrees...chances are it will stop being a function!...at least, in the sense of the new fnew(x) = trans(forig(x))
  8. Nov 13, 2011 #7

    I like Serena

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