To rotate a point \((x, y)\) clockwise about the origin by 90 degrees, you can use the following transformation:
\[ (x, y) \rightarrow (y, -x) \]
Given the point \((1, 2)\):
- Apply the transformation:
- The new x-coordinate becomes \(y = 2\)
- The new y-coordinate becomes \(-x = -1\)
Thus, the new point after rotating \((1, 2)\) 90 degrees clockwise about the origin is \((2, -1)\).