Apps. and Interpretation for IBDP Maths Ebook 1 | Page 63

Chapter
7
Arithmetic Sequences
7
SUMMARY POINTs
�
Properties of an arithmetic sequence u
n
:
1. u
1
: First term
2. d u2 u1 un
un
� 1
� � � � : Common difference
3. u � u1 � ( n � 1) d : General term ( n th term)
n
n
n
�
1� � �
1� : The sum of the first
n
n terms
2 2
4. S �2 u ( n 1) d� �u u �
n
n
� � ur � u1 � u2 � u3 � � un�
1
� un
r�1
: Summation sign
Solutions of Chapter 7
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