- #1

unscientific

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## Homework Statement

Taken from Binney's Text, pg 143.

## Homework Equations

## The Attempt at a Solution

From equation (7.36): we see that ##\delta a## is in the direction of the angle rotated, ##\vec{x}## is the position vector, and ##\vec{n}## is the unit normal to the plane of rotation.

But at the last line of (7.37), we see that ##\vec{\alpha} = \alpha \vec{n}##. Why is the angle rotated now the same direction as the unit normal to the plane?