Answer:
C is a linear function
Explanation:
To be a liner function, the change in y/ change in x must be constant
m =(y2-y1)/(x2-x1)
A
The x value does not change but has 4 different y values.This would fail the vertical line test. This is a vertical line so it is linear, but it is not a function
B (4-2)/(2-1) = 2
(8-4)/ (3-2) = 4/1
The slope changes between the points so it is not a line
C (6-8)/(1--1) = (-2)/(1+1) = -2/2 = -1
(4-6)/(3-1) = -2/2 = -1
(2-4) /(5-3) = -2/2 = -1
The slope is constant so it is a line
D (-2-2)/(-2--3) = -4/(-2+3) =-4/1 = -4
(4--2) / (-1--2) = (4+2)/(-1+2) = 6/1 = 6
The slope is not the same between these points so it is not linear