Answer:
horizontal line
Step-by-step explanation:
The equation of a horizontal line parallel to the x- axis is
y = c
where c is the value of the y- coordinates the line passes through.
The equation of a vertical line parallel to the y- axis is
x = c
where c is the value of the x- coordinates the line passes through.
Hence
y = - 1 is a horizontal line passing through all points with a y- coordinate - 1
