Question

Consider the four terms of the quadratic sequence What is the 5th Term 8 12 18 26

Answer 1

9514 1404 393

Answer:

36

Explanation:

First differences are the differences of successive terms:

4, 6, 8

so the next one is expected to be 10.

The next term is 26+10 = 36.

_____

The first-differences of a quadratic sequence are an arithmetic sequence, so have a common difference. Here, that "second" difference is 2.