Pre Algebra
posted by Colleen on .
What is the function rule when the input is 0,1.2.3 and the output is 5,4,3,2?

x: 0 1 2 3
y: 5 4 3 2
to get the function, we choose two points. let's just choose the first two points,, that is, point1 (0,5) and point2 (1,4)
now, we get first the slope. the slope is given by the equation,
slope = m = (y2  y1)/(x2  x1)
where
y1 = ycoordinate of point1
x1 = xcoordinate of point1
y2 = ycoordinate of point2
x2 = xcoordinate of point2
for point1=(0,5) and point2=(1,4)
y1 = 5 , x1 = 0 , y2 = 4 and x2 = 1
substituting,
m = (y2  y1)/(x2  x1) = (45)/(10) = 1/1 = 1
then we substitute it in the slopeintercept form equation:
y  y1 = m(x  x1)
substituting with y1 = 5, x1 = 0 and m = 1,
y  5 = 1(x  0)
y  5 = x
x + y  5 = 0
x + y = 5
hope this helps~ :)