To rotate a point \((x, y)\) counterclockwise by 90 degrees around the origin, you can use the transformation formula:
\[ (x', y') = (-y, x) \]
Given the point \(A(2, 6)\):
- \(x = 2\)
- \(y = 6\)
Applying the transformation:
\[ x' = -y = -6 \] \[ y' = x = 2 \]
So, after a 90-degree counterclockwise rotation, the new point \(A'\) will be:
\[ A'(-6, 2) \]