The y-intercept is the point at which a linear equation crosses the y-axis on the x=0 plot point. The equation to determine both the slope and the y-intercept of a line is y=mx+b. This calculation may ...

Horizontal lines run left to right, parallel to the horizon, with slope 0 and equation y = k. Vertical lines run top to bottom, perpendicular to the horizon, with undefined slope and equation x = k.