Analysis and Approaches for IBDP Maths Ebook 1 | Page 321

Exercise 51 51.1 (a) f �( x) �� 5e � f ��( x) � 25e � 5x 5x f ( x) �� 125e � (3) 5x (b) f ( x) �( � 5) e � 51.2 (a) f �( x) �� cos x f ��( x) � sin x (b) 51.3 (a) ( n ) n 5 x f (3) ( x) � cos x f (4) ( x) �� sin x (2 n) n�1 f ( x) �( � 1) sin x g�( x) � nx � n 1 g��( x) �n( n � 1) x n� g ( x) � n( n �1)( n � 2) x n� (3) 3 (4) g x n n n 4 ( n� 3) x n� (b) 12 51.4 (a) g�( x) � nx � ( ) � ( �1)( � 2) 1 g��( x) �� nx � 2 g ( x) � 2nx � (3) 3 g ( x) �� 6nx � (b) 36 Exercise 52 (4) 4 52.1 (b) � 2 � ��2, � � 9 � (c) 2 �k � 2 9 52.2 (b) ( �2, � 6) (c) k �� 6 and 2 2 k �� 3 52.3 (b) (2,1) (c) k � 1 and k � 3 52.4 (b) �5 � � � , � 2 � �12 � (c) 4 Exercise 53 53.1 (a) 10 (b) 16 53.2 (a) 3 (b) 13 36 53.3 � 3 53.4 2 4 e Exercise 54 54.1 54.2 54.3 54.4 7 640x 516311040x 6 560x 16x �3 Exercise 55 55.1 (a) x 2 �3x� 2� e � � (b) � 4.42 and � 0.763 (c) Refer to solution 55.2 (a) cos x� sin x (b) 0.785 and 3.93 (c) Refer to solution 55.3 (a) x x e cos( e ) (b) (1.23, � 3.29) (c) Refer to solution 55.4 (a) �x �x � e sin( e ) (b) ( � 1.59, 4.81) (c) Refer to solution 11 Front Page Answers www.seprodstore.com 313