Stupid Question About Finding the Angle of a Vector

AI Thread Summary
To find the angle of rotation of a vector in the first quadrant, the dot product can be utilized. Given the initial and terminal points of the vector, the angle can be calculated using the formula involving the dot product of the two vectors. The magnitude of the vectors remains constant, simplifying the calculation. The discussion emphasizes understanding how to apply the dot product in this context. This approach effectively determines the angle of rotation for the vector.
Saladsamurai
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:smile: Okay then!

Let's say we are ONLY working in the 1st Quadrant of the x-y plane. I have some vector in that region that makes some angle with the +x axis. I then rotate that vector through some angle.

The initial points of the vector before and after are coincident, i.e. I only move the terminal end to some new point while maintaining the vectors magnitude.

I know the initial point, I know the terminal points of both the original and new vector.

I now need the angle that I must have rotated through to get to the new point.

Is this a dot product problem?
 
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That's what it is.
 
:smile: Alrighty-then!
 
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