constant of variation

(p.264) the variable "k", in the equation: y=kx, is the constant of variation

direct variation

(p. 264) the formula: y=kx is the direct variation equation

negative correlation

(p. 298) as the variable "x" increases the variable "y" decreases

parallel lines

(p. 292) lines that have the same slope

perpendicular lines

(p. 293) lines that intersect at right angles

point-slope form

(p. 286) y-y1=m(x-x1)

positive correlation

(p. 298) as the variable "x" increases, the variable "y" increases

rate of change

(p. 258 tells on average how a quantity is changing over time

rate of change

(p. 258) tells on average how a quantity is changing over time

slope

(p. 256) a number determinded by two points on the line

slope-intercept form

(p. 272) y=mx+b