A line on the coordinate grid can be defined by a slopeintercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and yintercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the yintercept is the ycoordinate where the line crosses the vertical yaxis.
Which of the following is not required to define the slopeintercept equation for a line?
yintercept 

slope 

\({\Delta y \over \Delta x}\) 

xintercept 