To find the coordinates of point \( C \) given its reflection point \( C' \) across the x-axis, we need to recall how reflections across the x-axis work.
When a point \( (x, y) \) is reflected across the x-axis, the x-coordinate remains the same while the y-coordinate changes sign. Thus, if the reflection point \( C' \) has coordinates \( (2, -2) \), then the original point \( C \) must have the same x-coordinate and the opposite sign for the y-coordinate.
Therefore, the coordinates of point \( C \) can be calculated as follows:
- The x-coordinate of \( C \) is the same as that of \( C' \): \( 2 \).
- The y-coordinate of \( C \) is the opposite of the y-coordinate of \( C' \): \( -(-2) = 2 \).
Thus, the coordinates of point \( C \) are:
\[ C(2, 2) \]
So the answer is \( (2, 2) \).