Question

Write a function rule for the table.

x: -3,-2,-1,0
f(x): 1,2,3,4
A) f(x)=x+4
B) f(x)=4x
C) f(x)=x-4
D) f(x)=-4-x

Answer 1

y = x + 4 (Answer A)

Explanation:

Note that when x = 0, y = 4, so the y-intercept is (0, 4) Note also that as x increases by 1 from any given value to the next greater one, the 'run' is 1; the same behavior characterizes f(x). Thus, the slope of the line through the points indicated is m = 1/1 = 1.

Using the slope-intercept formula, y = mx + b, we get y = x + 4 (Answer A)