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