Math Academic VocabularyOnline version Quiz on math vocabulary terms. by Angela 1 A two-dimensional surface formed by two perpendicular number lines, the x-axis (horizontal) and y-axis (vertical), used to plot points. Yes No 2 Located where the graph crosses the x-axis and where f(x) = 0. Yes No 3 The horizontal number line on the coordinate plane. Yes No 4 The vertical number line on the coordinate plane. Yes No 5 A number that shows how steep a line is; it tells how much the line rises or falls as it moves from left to right, represented by m. Yes No