Page 78 - Past Year

76 | P a g e

16. (a) 20 (b) – Refer to Lecturer –

1
3x
2
dy 3e  x  3x   1 dy  3 2x  3 x   4 2
17. (a)  (b) 
dx x   3 2 dx 3x  2

18. f '(2) 
7

(x  2) (9x  3 70)
19. (a) '( )f x 
2 x  9

8(x  2) (2x  2 11)
(b) '( )f x 
(x  3) 2

3(2x  5)
(c) '( )f x 
2x  3


dy 4xy e 4 y dy  1
20. (a)  ; 
dx 3y  2 2x  2 4xe 4 y dx 16
(b) - Refer to Lecturer -

dy 7y  6xy 2 5
21.  , ,15
dx 6x y  2 2y  7x 2

2
e 5x 5x  2 x  15    3 5x  10x   2
22. (a) (b)
x  3 x  1 5x  2  2
2
7
23. ' f   x   4x  1, f '   2  

24. ' f   6x  x, 6

25. (a) - (b) A e

2 7x
26. (a) x e (7x  3) (b) ln x