Analysis and Approaches for IBDP Maths Ebook 1 | Page 64

Your Practice Set – Analysis and Approaches for IBDP Mathematics
Exercise 20
1. The first three terms of an arithmetic sequence are u1 � 12.3, u2 � 13 , u3 � 13.7 .
(a)
(b)
(c)
Find the common difference.
Find the 50th term of the sequence.
Find the sum of the first 50 terms.
[2]
[2]
[2]
2. In an arithmetic sequence u5 � 50 , u6 � 52 .
(a)
(b)
(c)
Write down the value of the common difference.
Find the first term.
Find the sum of the first 20 terms of the sequence.
[1]
[3]
[2]
3. In an arithmetic sequence u13 � 24 , u14 � 21.
(a) Write down the value of the common difference.
(b) Show that u �63� 3n.
n
(c) Find the sum of the first 3 terms of the sequence.
[1]
[3]
[2]
5 11 6
4. The first three terms of an arithmetic sequence are u1
� , u2
� , u3
� .
7 14 7
(a)
(b)
(c)
Find the common difference.
Find the 30th term of the sequence.
Show that
S
n
2
n �19n
� .
28
[2]
[2]
[2]
56
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