The distance from this line is designated by the ordinate.
The union of a function and its reflection over this line cannot be a function. The distance from this line is designated by the ordinate. The graph of a quadratic function with imaginary roots will never touch this line, which marks the boundary between the first and (*) fourth quadrants in a Cartesian graph. For 10 points, name this horizontal line, given as y equals zero.
The union of a function and its reflection over this line cannot be a function.
x axis (accept y equals zero or equivalents until it is read)