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Rotation matrices

  1. Jun 13, 2012 #1
    Show that a rotation by θ followed by a rotation by φ can be expressed as either
    two consecutive rotations, or one rotation of (θ + φ). That is, show that Qθ Qφ = Qθ+φ, where Q is the rotation matrix.

    Can any one answer this question I'm a beginner in Linear Algebra
  2. jcsd
  3. Jun 13, 2012 #2
    Re: Need Answer

    What is the rotation matrix with angle [itex]\theta[/itex]??
  4. Jun 13, 2012 #3
    do the matrix multiplication and see what happens
  5. Jun 13, 2012 #4


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    Science Advisor

    You will need the trig identities [itex]cos(\theta+ \phi)= cos(\theta)cos(\phi)- sin(\theta)sin(\phi)[/itex] and [itex]sin(\theta+ \phi)= sin(\theta)cos(\phi)+ cos(\theta)sin(\phi)[/itex]
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