Spotting a quadratic sequence

Taking differences twice, since a constant second difference is the signature.

The nth term of a quadratic sequence

Halving the second difference for the n² coefficient.

Higher

Using a quadratic nth term

Generating terms from a formula with an n² in it.

Higher

Practice

Spotting a quadratic sequence

Taking differences twice, since a constant second difference is the signature.

Practice

The nth term of a quadratic sequence

Halving the second difference for the n² coefficient.

Practice

nth term review

Linear nth terms found and used, and quadratic nth terms at Higher.

Mixed review