Mathematics for IGCSE & O level - Sequences (Section 1 - No. 22)
Which sequence represents a quadratic sequence?
2, 5, 8, 11...
1, 4, 9, 16...
3, 9, 27, 81...
1, 3, 5, 7...
Giải thích
Quadratic sequences are represented by a constant second difference.