- Thread starter Ys*
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As a hint, you'll probably want to review your class notes about rotations, specifically seeing if there's a section about rotating about some arbitrary point. You may also find

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To rotate (x, y) through angle \(\displaystyle \theta\) about the origin, do the matrix multiplication \(\displaystyle \begin{bmatrix}cos(\theta) & -sin(\theta) \\ sin(\theta) & cos(\theta)\end{bmatrix}\begin{bmatrix}x \\ y \end{bmatrix}\).

To rotate (x, y) through angle \(\displaystyle \theta\) about a point (a, b) that is not the origin

1) translate (a, b) to the origin using (x, y)-> (x- a, y- b)

2) do the matrix multiplication above to get the new (x, y)

3( translate back using (x, y)-> (x+ a, y+ b).

To rotate (x, y) through angle \(\displaystyle \theta\) about a point (a, b) that is not the origin

1) translate (a, b) to the origin using (x, y)-> (x- a, y- b)

2) do the matrix multiplication above to get the new (x, y)

3( translate back using (x, y)-> (x+ a, y+ b).

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