Jacqueline leaves city a at 2: 00 p. m. and drives at a constant speed, traveling west on i-90. she passes city b, 40 mi from city a, at 2: 50 p. m. (a) find a linear function d that models the distance (in mi) she has traveled after t min.

Ans : Linear functions are those whose graph is a straight line. A linear function has one independent variable and one dependent variable. The independent variable is x ( which is the distance Jacqueline travels ) dependent variable is y ( which is Speed, in mi/h ) Now the equation becomes : Speed (y) = Distance (D) / Time(X). Then the speed at which Jacqueline traveled : y = D/X y = 40/50 = 0.8 mi/minute = 0.8 x 60 = 48 mi/hour. We create a liner function and the two variables are x (Independent, Time) & y (Dependent, Speed). (D) is the coefficient of the independent variable x.