Analysis and Approaches for IBDP Maths Ebook 1 | Page 164

Your Practice Set – Analysis and Approaches for IBDP Mathematics
55
Paper 2 Section A – Graphs of
the derivatives of functions
Example
Let
� � � , for �1� x � 3.
2
x
f ( x) 2.5x 3x e
(a) Write down the expression of f� ( x)
.
(b) Find the x -intercepts of the graph of f � .
(c) On the grid below, sketch the graph of f � .
[1]
[3]
[3]
Solution
(a)
x
f �( x) � 5x �3� e
A1 N1
(b) f�( x) � 0
(M1) for valid approach
x �� 0.475711 and x � 2.8469186
x �� 0.476 and x � 2.85
A2 N3
(c) For correct shape A1
For approximately passing through (0, 2) A1
For approximate range � 2.4 to 6 A1 N3
[1]
[3]
[3]
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