Analysis and Approaches for IBDP Maths Ebook 1 | Page 43

Front Page
12
Paper 1 Section A – Using laws of logarithm
to perform simplifications
Example
Find the value of each of the following, giving your answer as an integer.
(a) log9
729
(b) log9162 � log92
[3]
1
(c) log9 log94
36 � [3]
[2]
4
Solution
(a) log9
729
3
� log9
9
(A1) for valid approach
� 3
A1 N2
(b) log9162 � log92
162
� log9
(A1) for correct formula
2
� log 81
9
2
� log9
9
(A1) for valid approach
� 2
A1 N2
1
(c) log9 log94
36 �
1
� (A1) for correct formula
log9
9
1
log9
9 �
� (A1) for valid approach
�� 1
A1 N2
[2]
[3]
[3]
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