What is the equation of the following linear function?

  x = 4

Step-by-step explanation:

A vertical line has an equation of the form x=constant. The constant value can be read from the graph as being 4, so the equation is ...

  x = 4

The relation does not pass the vertical line test. (A vertical line intersects the graph in an infinite number of points, not just 1.) So, this is NOT A LINEAR FUNCTION.

y=-1/2 x +4

Step-by-step explanation:

find the slope of the line :

(5,6), (8,12)

m=y2-y1/x2-x1

m=12-6/8-5 = 6/3=2

find b : y=mx+b at a point 5,6

6=2(5)+b

b=-4

the function of the table is : y=2x -4

the slope of perpendicular line is opposite reciprocal :

y=-1/2 x +4 ( y=b when x=0)