Question

QUESTION 1 1.1 Consider the quadratic sequence : 8; 18; 30; 44 ... 1.1.1 Write down the next two terms of the sequence. 1.1.2 Calculate the nih term of the sequence. 1.1.3 Which term of the sequence is equal to 330?

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Answer 1

Below in bold.

Explanation:

8 18 30 44

the differences are 10 12 14 .etc

1.1.1 Next 2 terms are 44+ 16 = 60 and 60+ 18= 78.

1.1.2 8 = 1^2 + 7

18 = 2^2 + 14

30 = 3^2 + 21

44 = 4^2 + 38

So the nth term = n^2 + 7n.

1.1.3 n^2 + 7n = 330

n^2 + 7n - 330 = 0

(n + 22)(n - 15) = 0

n = -22, 15

As the term sequence must be positive the answer is 15.