Analysis and Approaches for IBDP Maths Ebook 2 | Page 37

9
Example
Paper 1 Section A – Transformations of Roots
2
3
The real root of the equation x � 2x�5 � 0 is 1.3283, correct to four decimal places.
Determine the real root for each of the following.
(a)
(b)
3
( x�5) � 2( x�5) �5 � 0
1
3
8 x x
� � 5 � 0
[2]
[2]
Solution
(a)
(b)
The required real root
�1.3283 � 5
(M1) for valid approach
� 6.3283
A1
The required real root
� 2(1.3283)
(M1) for valid approach
� 2.6566
A1
[2]
[2]
Exercise 9
1. The real root of the equation
each of the following.
3 2
4x 19x 10x
50 0
� � � � is 1.25. Determine the real root for
(a)
(b)
3 2
4( x � 6) �19( x � 6) �10( x � 6) �50 � 0
� � � � �
3 2
4x 19x 10x
50 0
[2]
[2]
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