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    Hi, could someone please help with this question please:

    If T rotates each point through an angle theta about the x-axis in the direction that moves the point (0,0,1) towards the point (0,-1,0), find the matrices representing the geometrical transformation
    T:R^3 ->R^3 with respect to the standard basis.

    Any help would be greatly appreciated!
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    Hmm .. you're not getting many takers, so I'll try

    Rotation matrix in 2D is easy

    You really have a 2D problem here.

    Isn't it just a question of padding out some 2D rotation matrix to make it a 3D one?
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    I'm not sure, how would you do that anyway? All we're given about anticlockwise transformation in 2d is just
    (cosx -sinx)
    (sinx cosx) I'm not sure how to apply that in 3d...

    My understanding is just to work out whether T is an anticlockwise or clockwise transformation, but surely it could be either depending on which way you look at it?
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    Well, I think the x co-ordinate is unchanged by the rotation. So we're looking for a matrix of the form (1,0,0/0,?,?/0,?,?)

    If you just considered the y and z co-ordinates as a 2D problem, would you be able to construct that rotation matrix?

    And if you were worried about clockwise/anti-clock, you could always just try the numbers?
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    Thank you, that's actually quite helpful!
 
 
 
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Updated: February 8, 2010
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