Question

If there are 5 terms in a quadratic sequence

0.2, 0.8, 1.8, 3.2, 5.0.....
What is the next term in the sequence?

Answer 1

7.2

Explanation:

First differences:

0.8-0.2, 1.8-0.8, 3.2-1.8, 5.0-3.2

0.6, 1.0, 1.4, 1.8

Second differences:

1.0-0.6, 1.4-1.0, 1.8-1.4

0.4, 0.4, 0.4

For the next term, add 0.4 to the last term from the first differences, and add the sum to the last term of the quadratic sequence:

0.4+1.8=2.2

2.2+5.0=7.2

∴ The next term in the sequence is 7.2