\Describe and correct the error a student made when finding the function rule for the data in the table.

Question

X= 1,2,3,4

Y=10,19,28,37

Answer 1

You did not state the student's error, but to express y as a function of x,

y = 9x + 1 {for x = 1, 2, 3, 4}

Answer 2

f(x) = y = 9x + 1 = 10 + (x-1)(9)

f(1) = 9+1 = 10

f(2) = 9(2)+1 = 19

f(3) = 9(3)+1 = 28

f(4) = 9(4)+1 = 37

It's a linear function with slope = 9 and y intercept = 1