Part a: Reflecting a point across the x-axis, changes the sign of the y-coordinate.
Part b: Reflecting a point across the y-axis, changes the sign of the x-coordinate.
Part c: Reflecting a point across both the axes, changes the signs of both the coordinates.
Explanation:
Part a: Reflecting a point across the x-axis
The reflection is a transformation of a figure which represents a flip.
The rule for a reflection over the x -axis is given by

Hence, this represents the change of sign of the y-coordinate.
Thus, Reflecting a point across the x-axis, changes the sign of the y-coordinate.
Part b: Reflecting a point across the y-axis
The rule for a reflection over the y -axis is given by

Hence, this represents the change of sign of the x-coordinate.
Thus, Reflecting a point across the y-axis, changes the sign of the x-coordinate.
Part c: Reflecting a point across both the axes
The rule for a reflection across both the axes is given by

Hence, this represents the changes the signs of both the coordinates.
Thus, Reflecting a point across both the axes, changes the signs of both the coordinates.