Analysis and Approaches HL Practice Paper Book | Page 20

Your Practice Paper – Analysis and Approaches HL for IBDP Mathematics

7

Arithmetic Sequences
� 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

8

Geometric Sequences
� Properties of a geometric sequence u n
:
1 . u
1
: First term 2 . r � u2 �u1 � un
� un
1
: Common ratio
3 .
u u r
n 1 n
1
� : General term ( n th term )
4 .
( 1
n u )
1
� r
Sn
: The sum of the first n terms
1� r
5 .
u1
S
: The sum to infinity , given that
1
1
1� r

9

Binomial Theorem
� Properties of the n factorial n !:
1 . n! � n�( n �1 ) �( n � 2 ) � �3�2�
1
2 . 0 ! � 1 3 . n! � n�( n � 1 )!
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