The first three terms of an arithmetic sequence are 3, 7 and 11 - HSC - SSCE Mathematics Advanced - Question 11 - 2023 - Paper 1
Question 11
The first three terms of an arithmetic sequence are 3, 7 and 11.
Find the 15th term.
Worked Solution & Example Answer:The first three terms of an arithmetic sequence are 3, 7 and 11 - HSC - SSCE Mathematics Advanced - Question 11 - 2023 - Paper 1
Step 1
Find the common difference, d
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Answer
To find the common difference, we can subtract the first term from the second term:
d=7−3=4
Step 2
Identify the first term, a
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Answer
The first term, denoted as 'a', is:
a=3
Step 3
Calculate the 15th term, t₁₅
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Answer
Using the formula for the nth term of an arithmetic sequence:
tn=a+(n−1)d
we can find the 15th term: