The set of ordered pairs represents a function. Write a rule that represents the function? (0,0), (1,5), (2, 40), (3, 135), (4, 320). Y=?

1 Answer
Mar 9, 2018

#y = 5x^3#

Explanation:

Firstly, we have to find a pattern. It does look like all values of #y_x# are multiples of #5# and of #x#, but what else ?

Since #y_x# is a multiple of #5# and a multiple of #x#, we can divide #y_x# by #5*x# to get :

#y_1/(5*1) = 1=1^2#

#y_2/(5*2) = 4=2^2#

#y_3/(5*3) = 9=3^2#

#y_4/(5*4) = 16=4^2#.

You can clearly see a pattern here ; #y_x/(5*x) = x^2#.

Therefore #color(red)(y = 5x^3#.