Linear Algebra: Rotation Matrix Qθ+φ

camchetan
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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 anyone answer this question I'm a beginner in Linear Algebra
 
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What is the rotation matrix with angle \theta??
 
do the matrix multiplication and see what happens
 
micromass said:
What is the rotation matrix with angle \theta??

genericusrnme said:
do the matrix multiplication and see what happens
You will need the trig identities cos(\theta+ \phi)= cos(\theta)cos(\phi)- sin(\theta)sin(\phi) and sin(\theta+ \phi)= sin(\theta)cos(\phi)+ cos(\theta)sin(\phi)
 

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