Question

Find the nth term of this quadratic sequence 2,8,18,32,50

Answer 1

2n²

Explanation:

Since the sequence is quadratic we know this must involve an n² term

Consider each term

n = 1 → 1² = 1 → 1 × 2 = 2

n = 2 → 2² = 4 → 4 × 2 = 8

n = 3 → 3² = 9 → 9 × 2 = 18

n = 4 → 4² = 16 → 16 × 2 = 32

n = 5 → 5² = 25 → 25 × 2 = 50

n = n → n² → n² × 2 = 2n²

Thus the n th term is 2n²

Answer 2

= 2n²

Explanation:

From the sequence 2,8,18,32,50

The difference between each numbers are

: 6, 10, 14, 18

The difference between the second sequence is 4.

Therefore the nth term of the sequence is 2n²