The first five terms of an arithmetic sequence are
1 4 7 10 13
Write down an expression, in terms of n, for the nth term of this sequence. - Edexcel - GCSE Maths - Question 2 - 2020 - Paper 1
Question 2
The first five terms of an arithmetic sequence are
1 4 7 10 13
Write down an expression, in terms of n, for the nth term of this sequence.
Worked Solution & Example Answer:The first five terms of an arithmetic sequence are
1 4 7 10 13
Write down an expression, in terms of n, for the nth term of this sequence. - Edexcel - GCSE Maths - Question 2 - 2020 - Paper 1
Step 1
Write down the formula for the nth term of an arithmetic sequence
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Answer
In an arithmetic sequence, the nth term can be calculated using the formula:
an=a+(n−1)d
where:
a is the first term of the sequence.
d is the common difference between the terms.
Step 2
Identify the first term and common difference
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Answer
From the given sequence (1, 4, 7, 10, 13):
The first term a=1.
The common difference d=4−1=3.
Step 3
Substitute the values into the formula
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Answer
Substituting a and d into the nth term formula gives: