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November 26, 2014

Homework Help: maths

Posted by ashely on Saturday, February 11, 2012 at 2:07pm.

r1 and r2 are unit vectors in the x-y plane making angles a and b with the positive x-axis.by considering r1.r2 derive
cos(a-b)=cos(a)cos(b)+sin(a)sin(b)

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