Question

Look at this function:


x y
−3 −8
−2 −6
−1 −4
0 0


Matt said that the function is linear.

Justine said that the function is nonlinear.

Which of the following explains who is correct?
Matt, because for every 1-unit increase in x, there is an increase in y by 2
Matt, because for every 2-unit increase in x, there is an increase in y by 1
Justine, because the point (−3, −8) does not lie on the straight line that contains the other points
Justine, because the point (0, 0) does not lie on the straight line that contains the other points

Answer 1

Justine, because the point (0, 0) does not lie on the straight line that contains the other points.

Explanation:

See the graph below. The following coordinates are not in a stright line.

Hence, it is a non linear function. Justine is right.

When drawn a straight line. the coordinates: (0,0) does not lie on the line.