Question
(a) Write down the next term in each of these sequences.
(i) 5 9 13 17 . . .
▶️Answer/Explanation
The given sequence is an arithmetic sequence where each term is obtained by adding a constant difference of 4 to the previous term.
So, the next term in the sequence would be:
\(17 + 4 = 21\)
Therefore, the next term in the sequence is 21.
(ii) 3 6 12 24 . . .
▶️Answer/Explanation
The given sequence is a geometric sequence where each term is obtained by multiplying the previous term by a constant ratio of 2.
So, the next term in the sequence would be:
\(24 \times 2 = 48\)
Therefore, the next term in the sequence is 48.
(b) Here are the first four terms in a different sequence.
2 7 12 17
Find an expression for the nth term of this sequence.
▶️Answer/Explanation
The given sequence is an arithmetic sequence where each term is obtained by adding a constant difference of 5 to the previous term.
To find an expression for the nth term of this sequence, we can use the formula for the nth term of an arithmetic sequence:
\(a_n = a_1 + (n – 1) \cdot d\)
Where:
\(a_n\) is the nth term of the sequence.
\(a_1\) is the first term of the sequence.
\(n\) is the term number.
\(d\) is the common difference between consecutive terms.
In this case, the first term \(a_1\) is 2 and the common difference \(d\) is 5.
Substitute the values into the formula:
\(a_n = 2 + (n – 1) \cdot 5\)
\(a_n = 2 + 5n – 5\)
\(a_n = 5n – 3\)
Therefore, the expression for the nth term of the given sequence is \(5n – 3\).
Question
(a) 2, 3, 6, 11, 18, . . .
(i) Write down the next two terms in this sequence.
Answer/Explanation
Ans: 27, 38
(ii) Describe, in words, the rule for continuing this sequence.
Answer/Explanation
Ans: Add the next odd number oe
(b) The nth term of a different sequence is 4n – 3.
Work out the first three terms in this sequence.
Answer/Explanation
Ans: 1, 5, 9
Question
Find the next term in each of these sequences.
(a) 3, 7, 11, 15, …
(b) 10, 7, 4, 1, …
(c) 1, 9, 25, 49, …
Answer/Explanation
Ans:
(a) 19
(b) -2
(c) 81
Question
35, 41, 47, 53, 59,
For this sequence, write down
(a) the next term,
(b) the nth term.
Answer/Explanation
Ans:
(a) 65
(b) 6n + 29 oe