Answer Key
Answer Key
2, Let S 1 and 5l represent the distance travelled in air and in water respectively. Then find an expression for t, the
time taken.
Chapter 13 Differentiation of Trigonometric, Exponential and Logarithmic Functions and their Applications
Chapter 14 Integration
3. Write down a definite integral to find the area. What do you observe about the terms within the integral?
Chapter 16 Kinematics
99
.........__
Hin b fo r ChaUcnge Yourself }
E
...
Answer Keys
Chapter If c;raJic-nh, _ (a) 6 x~ +6x =+ 6 12. (o) /1 = - 1. k = - 6
2 (d) 6(x+S-6~ )' ( 1---l_)
Oct'ivatn1..~ anti (b)f:i111=- l. 11 = I
(3x+ l )' I[;,
Ditkrent,atiun r\.'1.:hn1qu"~!i. 13. (i) (2. 19). (-2. -25)
Sx- 16
)-j (1-f)
(b)
PractisC' N o w 1 (ii) O (iii) 7 (c) ½( x +f
3~( 2x- s )'
I
(a) -7 I
6x ' + 3x+ l4
I
l./x
I
(b) 3ef;' (c) _
Jcix' - 7)'( 1+ 4x )
14. (a) (b) 3 l/x' (0 ¥J<Jx-1)'
I
(c) 0 (d) -74 15.x < l orx > J 8. e ,, = -2x +3
3
3. .2;..
37>7 9. (2. 2)
(c) -2-Jx' (0 o E.~r.rci sc 11 B "
4 3
Practi se Now 8 I. (a) 14 (2 < + S) , 10. (i) --+-
2x -5 x+l
(b) -32(3 - 4.,·i
Practise Now 2
I. (i) 15., 0 - t\x; 30x - 6 (ii) _ _ _s_ __--2_
.. 2 (c) m x - 4) ( 2x- s )· (x +l )'
I. (a) -2,. + _l_ (u) x >
5 5
x· 3ef;' I (d) 27(x + 4)' I I. a=
4 .b= - 3
2. -
3
or I 4
(b) - ~ + a (e) -15 (5
. ., - 3)' IJ. O < x < l6
3x"
Practise Now 9 4 '
2.
-R+ 2Jx
4 3
3 - 3x : : x < -l o r x > l (0 i(i- 1) Exercise I IC
I. (a) -9., 0 - 4x + 6
(x ' +1 )' 3
2. (a) - (3x+2 )' (b) (Sx + 1)' (40x + I )
Practise Now 3
Practise Now 10 (c) 2(x - 3)'(5x + 3)
I. 28 30
Q ::!S. X <2 (b) ( 2-Sx )' (d) 3( I + Sx)'(S0.,0 + 4x - 5)
2 I
. 6 2. IS
Exercise 11 A 72 x
I
(c) - (2+ 3x ' )' 3. - 3, 5 or -
Practise Now 4 I. (a) IOx'
(b) 4l/x' 11
I. a= 8. b = 3 6x 7 __1_
4.
2. a = 5. b = - 6 (d) _2_ (d) - (x' + 2)' 2Jx
(c) O
x• 24-105x J
60 5.
Practise Now 5 2 (a)
(c) - -- (0 0 (c) (3 -4x )'
I. (a) 84x'( 4x' - I)' 31./x'
9x (b) 12x ' -2x+9
4 ( 2x+3) 2. (a) IOOx ' +~ (O 2(5- 3x ' )' .J2x' +3
(b) .Jx' +3x-4 X
(0~
4 (x ' +J )'
A ns wer Kc-rs
200
1111111111
ExC"rdsc 11 F 9. a = - 16.5, b = 54 Practise Now 12
.\ - ,\
J. (R)
i.<• l ~
X
(c) x < - I
> -5 (b) X > 2 10. Increasing
(ii)H.7)
6.\' 1 + IO
(d) x < 3 or x > 5
(b) - ~ Practise Now 13
(e) x < - 3 or x > 4 Ch.1ptcr 12 Applic,1tions of
x-6 (iii) r = 2.8,
5 Differentiation
(0 - I < x< I minimum A = 65. t cml
(d ~
(x-3 )' Practise Now 1
7
2. (a) X < I (b) x > - Practi se Now 14
d) Jx' +4x 4 1 y= -Ix+~· y = Ix+!.!.
. 2 4 ' 3 2
(2 ~
(x+ ll (C) - 4 < X < 2
5 13 9 49
= 7 -lr (Ii)
(I) £! cm'
16
. I (ii)!.
(d) - 1 <X< 2 2· y = 9x-9 ;y = -sx•rr r
3, (1) 9 25
(e)
3
-I < x < 4 Practise Now I 5
l , 8/1 :2, k •- I Practise Now 2
3 (i) .J251 ' -2601+680 m
(ii) Yes (0 x < - l or x > I
s. (i) 7 I. (i) l;y=-x-4
(ii) I = 5.2, m inimum distance=
6. 6.32 units 3. 0 < X < )
4
(ii)( I, -5) (Iii) ¾ 2m
7, (i) (.,0 + 5)(x - I)
4. x>3
2. (i) y= -¾x+2 Exercise 12A
( i xi·)+S
~ .x-
~1 5, (i) -3 < X < 2
3,o).
(a) y= 5x- 7
(ii) -8 1 or44 (ii) A( 2 8(0, 2); ( 1}, I) I.
(b)y=-16x
{iii)~-~
J(x' , s)' 3(x -1 )' 6. e -2x' - I Ox (iii)No (c) y= 2
7. (i) 0 < X < 7
1 I
9. (I) -H!::!!:,
k- X 8. 0 < x < 3 or x > 6 Practise Now J (d)y= Ix-I
9. (a) B (b) C 2; (-0.451, -0.823), (-2.22, J.82)
2 (a) y = __!..,x+~
E.xrrdsr tl E (c)A ' 10 10
Practise Now 4
1. (a) 12.,0 ; 36.," (b)y= -9x+~
(b) S; O (c) 6x + 5; 6 Review Exercise 11 I. 4 3
I 2 67 (c)y=x+2
I
(d)-,; ' I. (a) - (b) 18 2. 2
X X 4 (d)x = .!_
(c) 30(3x + 2)'; 8l0(3x + 2)' 3
I I
(c) 2.
16
(d) 0 Practise Now 5
7 4 79
<o--
20 ,--=-
4J(x-4 )' (e) -5 (f) -13, 13 (i) 9.6rr cm' /s (ii) 57.6rrcm' /s 3. y =
4 x+l;y= -
7 x+IT
. 23 3 446
I 2 2, (a) 6(ax' + bx)' (2ax + b) Practise Now 6 4 · (,) 3 ;y = -23x+23
l. (a) l-7 ; ?° (b) 10(2ax + b)'(5x' - ab)'
(i) ~rr cm/s (ii) 5 cm'/s ") 23
2 I 2 6 (l 7ax' + 6bx - a'b) 3 (II -82
(b) 7 -7 ; 7-7 2abx~ +2b x +2acx 2 3 2
(c)!l,.Jx' __1_,
(c) - ,
(bx' -ex)·
Practise Now 7
(-1, 10), maximum point;
5. (½,4)and (-½,-4)
2 2,JX
(d) acx' +2bcx+a' (3, -22), minimum point 6. er= 5x
~.fx+-1- (cx' -a ')' 7. y =X 5; (0, -5)
4 4-Jx' Practise Now 8
-
7
3. (a) 25(5x - 4)'; 500(5x - 4)' 8. y= 2x- 7; 4
1 _ _ ; _ 2_ ,
(d) _ _ (0, 0), point of inflexion;
(x -1 )' (x -1 ) b ) ~ · 3x'+30x 9. a = 2, b = -3, c = 5
( ,.---,-; ' 3 27) . . .
v2 x +5 v C2x' +5l ( 4.- 256 , mm1mum pomt 10. (i) y= 3x-5
(c)-~ ; ~
(x-4 ) (x -4 ) 150x 2 +45
(c) 15xv,x- +,; .J5x "+3
, Practise Now 9 (ii) (½ , -1¾)
(O x' +2x . _ 2_
(x+I )' , (x+I)' (d) 6x ; 12-18x
2
(i) (½,-~)and (-4, 159)
12. (i) h = 2, k = l
3. (I)
. (3
4' 3sI) ' (-4•-ls
I 5) 1(2+9x' )' 1(2+9x ' )'
") (I3•- 327
( 11 20) ,mm1mumpomt;
. . .
(ii) (¾,2¾)
(e) _ _2_7_.
13. Yes
(ii) 152 (3x-5l'' (3x-5)' (-4, 159), maximum point
14. (29.3, 8.58)
S. • • 16,b, 226
(O 3x+34 ; - ~
Practise Now 10
7. (i) ~.fx +.2_ . J <2x+9)' j (2x+9)' Exe rcise 128
2 Jx' (3, 1), point of inflexion;
I. 0.268
3 I
4. (½ , -1½), (-½,1½) 3 11 ) . . . 2. 6x' - l 2x + 4; x .;; 0 or x ;;,, 2
4.fx-2,R ( 4 ,-16 128 , mm,mum pomt
4
(ii) No (iii)No 5. a = V, b = -l 3. 4rr cm'/s
s. e-x' 6. I 2r' - 6r - I 8; -I < r <
2
Practise Now 11 4. 120 cm'/s
1
Minimum gradient= -31.4, 5.
7
·
5
18' 5
8
x= 1.6 12 cmls
8. (i) Increasing 6. (i) 3.6rr cm'/s
Answer Keys
201
1111111:
1x')
19. (i) °"'-.-rea.-., (ii) No
(iii) -6-lSk crn/s
J>'"""'lint
(d) (-2, -6). point of inflexion;
10. (ii) (15x-
(iii) 937.5 cm'
cm' (b) 12xsec '(3x -
1 )+
El.~rci.~ tl:C
(2. -6). point of intle.xion;
(0. -70). minimum point
11. (ii)224 cm 4tan(3x-})
13. 6. 16 unit'
I. (a ) {-1}.-1{).minimum 9. (i) 6.\ - .lOx + 36: (l. 35).
0
14. (i) S275
(c) l0sin-l xcos5x - 8sin5xcos4x
sin 1 4x
(3. 34) 15. (i) 8km
point 2. sec n.x (nx tan nx + 1)
(ii) 1lx - 30; (2. 35),
(b) ( I. -2). m:i.-cimum point ma.timum point; (3. 3-t). Re,icw Exercise 12 Practise Now 3
(c) {1½ - - 3¼) . minimum
minimum point 1. 24.\.! + 22x - )0, -35 < X < 43
10. (i) a= I. b = 16 (a) - 20 cos ' (5x) sm
. (5x)
3 9 9
-3, 89I)'
1 27)
(ii) Minimum point 2. (i) (I, 0), ( 4•-128
. ( l
pomr~
11. (i) p = -4, q = -1 (ii) (I, 0), point of inflexion;
(b) ~sin'(~),o{;)-
maximum point
(ii) (-+-34¾) I 27)
( 4,- 128 , minimum 20tan( 2x+} )s~ 2x+%)
1
(}.s). minimumpoint: (
(h) ( I. -6), point of inflexion (iii) Minimum point 8. (i) ½(18-3x+l2x ' -2x '); (d) 2e'' '' (cos 2x - sin 2x)
1. (al ( I. 6). maximum point; (iv)96 e' '' '(5x-l )
(2~ S). minimum point ·i 33 _ .!.(-3+24x-6x ')
I 3 . (1 p = -T . q = 54 2 (e) 3x'
(b) (i-, ·27-'' ). minimum
_/
(ii)(9, -120.5) (ii)..!..unil/s
I05 (f) _.!_,,,, .. ,
2·
poin t: (iii) (2. 51), 9. (ii) Greater
\ o,...,n Kt"n
202
' ..........
6. (a) (2ax+b )e u'••• 6. (i) -3 sin x - 5 cos x
prscti" Nows 7. (a) ~ , x ' sin ( -}x ) +
(b) -e•'-• (ii) 2. 11 (iii) Minimum
Je, -
1- i .b4
2 nx cos
).. 0. 198 (c) ~ er.;:; 7. (a) ( 2le)
2 X
Je(ln(e' +6))' (b) 4 cos 3x sec' 4x-
(d) ne ' (b-1)
(¼, -¾)
3- ~ 3 tan 4x sin 3x
(c) 10 , 8. (b)
practis< Now 9
11
(sinS x +cos5x )· 9. (ii) I
I. )
·=Jx +-+-
12 2 '
8. (i) 4 (ii) y =-.!.x+2
4
-4 sin .!. x- (9-x lcos.!. x
(d) 4 4 Exercise 13C 9. 2+48./3
y = -~ x+ ~+ . ' Ix
3 36 2 4 sm I. (a) _I_ 10. (i) -4. 12 units/ s
4 x-5
(b)~
x' -3
).. 5 (ii) Decreasing
8. (a) sin!:_!:cos!:
J. A(!, l ),y: - lx+ 3 X X X (c) 2x-2 (d) 1 I. (i) 28.3 g (ii) 29.2 days
x 2 -2x 9x-l
(b) 3a tan' (ax+ b) sec' (iii) 0.593 g/day
practise Now IO (ax+ b) 6 I
23 (e) 2x+ 7 (O 2(1+x) 12. -0.0540 thousand units/
1· (i) (3x-4 )(2x +S) (c) a cos ax cos bx - month; -0.00 I I 7 thousand
b sin ax sin bx (g) _.!. 2
(h) 5-2x
units/month
X
(ii)~units/s (d) acosax cos bx +b sinax sinbx 13. 4 watts/s
(i,-./2) ,
23 cos 2 bx 2. (a) -tan x
9. No (b) sec ' x- 7 cosx 14. (i) (f,-1) ,
l.
./3 units/s IO. 8P = 8, q = l or p = -16, tanx- 7 sm x
(3411 ' -./2)
5
q =-2 (c) _ _ 3___ 1_
3. 3(1 - lx)e·" - !Se·" ,
11. -4.99 2(3x-l ) 2x+l
-10.0 units/s
Practise Now 11
12. -1.73 2
(d) 3x - 3(5x+4 )
5 (ii) ( f, -1) , maximum;
13. a= 5, b = -10, c = -10
I
2x 1 +7 x 18. l <X< I
(c) 6sin 2 X
I
I_ (d) e.r - ~
(c) _ _ (0 -2 tan 2x
(d) 5(4 tan x + nx)' 19. (i) - 33 (ii) _73
(4 sec' x + n)
2,R e 5. 11 x+l
3. (a) e",,, cos x 6. (a) !Ox'(! + 4 In 5x) (iii) 0
2. (a) 28 cos 7x - I
(b) -2e='-' sin 2x 20. i-+,fj
(b) (I+x ')' +6x(l+x' ) 2
(b) 24sec '(3x-i) (C) 4e• 1ua SeCl X x+e 21. (ii) 1.07 (iii) Maximum
(d) 3(cosx + sin x)e''"'•'M' ln (x+e) 22. (i) 50(28 + sin 20) cm'
(c) Ssi~Sx
cos· sx 4. 5 (ii) 15 cm'/s
(c)-1-
(d) _ 9sec,' 0.9x 5. (a) x(x + 2)e' x-.fx 4kr'
23. - -- cm' /s
tan · 0.9x (b) e'(cos x - sin x) 5
(d) 1-l~x
3. (a) -4 cos' 3x sin 3x (c) e'(2 cos 2x + sin 2x) sx·
7. (a) -308 (b) 2.12 Review Exercise 13
(b) 14tan'(2x--i) (d) -2e' sin x
8. 3.41 ; 2.72 I. (a) 211 - 2n sin nx
(e) xe""' (½xcosx+l) (b)2 cos 2x
sec '(2x-'i) 10. -0.009 00
5. h~ B,k:6
2,R Y = -5x+2+ 30 (I)---
,-
x x·+2
2. y=2x+ I 2 I , I
3 tan 3xsec · 3 x+
( g)
3. 2;y = 2x- 2
4. (4, 0)
9
2xsec ·•(I3 x )'
5. (i) 4,fj (ii) 0.416unit/s
p
Answer Keys
203
........___
2. y= ~x • -lx 1 +2x-~ 2. (i) .J I
(h ) __12__ 3 2 6 x 2 -l
2 Se h - l
2. (a) cos' 7x si n 4 x I. (a)~ Practise Now 4 (ii)¾ ln {x+R:-i)+,
(5 cos 7xcosx-
2j;>;i
') 12 ,,;: I ,
(b) (6 - x)' (48x - 36x' - i) (1 R = s <JX + 2 x
2S si n 7x sin x)
3. (ii) (x ' +~)-J3x-2+c
x cosx - 2si n x (a) e..'\4 + 4 cos x - sin x) (ii ) $740 000
(b) - -. 2.
X
(b) - 2- Practise Now 12
(c) O.J(ln5x + n)sec' O.Jx + coslx Practise Now 5 (') 2 3
I. ;::-i+h+)
(¾.1)
I
.!..ran 0.3x (a) I ( 5x+4 )" +c
X
(d) -3e-6l(sin 3x + 2 cos 3x)
3. 60
(ii) 2ln(x-l)+
(e) x'c"( 2x + 3) + 2e~(4.x + I) 4. d = 2, b = 0 (b) 5J3x+5 +c 3
(0 k " (ln .J2x )
6. JO 2 In (2x +3 )+c
7. (i) 9-_!,;
X
.!,
X
(c) - ~
3(4 x-7) '
+c
2 .!.1n (3x -2 J- ~ + c
(;-ln.J2x ) · 3 2(3x-2)
(ii) (}, 6)minimum .
4. (½,in¾) Practise Now 6 Pract ise Now 13
Jsin x+cos x
(-}.-6) maxi mum y= ' (1- 2x) +x
5
' (ii) 2x + 2 sin x + c
5. (i)
e" 8. 0.340 cm/s
(ii) 2 82, 5.96 Practise Now 7 Exercise 14A
9. AB = 40 m, BC= I 20 m
5 3 . I I , 3 ,,---.
6. (i) 0.0 109 units' (a) -4cos4x+2smzx+c I. ( a) x +c (b) vx• +c
6 4
(ii)E2 ( ~
3 '
_ _!_)
Jj (b)
I
tan3x-x+c 2 . (a) --2,+ c (b) ~1[7 +c
Rt'\ iMOO £'\.cri:-he E2 3 9x 5
¾R
5
7. x < - 3 2
6 I. -28 units/s (c) zx 2
+21tan6x +c (c) +c (d) {x' +c
8. Ir= 4, k = 2 I+ln!Ox
2. (a) lnW
Jj 3. (a) ¾x' +3x+c
9. -JO uni t/s Practise Now 8
10. Sx 2 _
!Ox
; -
15 .
umts/s
(b) Stanx-(5x+ J)sec' x
tan 2 x I. (a) ¾R +½sin(Sx+3)+ c (b) 2x' +:!..-2Jx +c
X
4 8 3. a= 5, b = -2 I
(b) 2x- cos(3x+n)+c (c) .!.x' _2...+c
4sin x -l
4. (i) 1-~ (ii)~ 3 4 2x
II . (i) (sinx - 4)' 2
t
3
min value = - -4 -
3,/3 (b) -¼e'-" +c (c) ~(Sx-6)' +c
45
1
16. Min concentration = (c) x- - -+ c (d) 1o~(2x+7 )'
Chapter 14 Integration )e h
2-./2 units, I= ¼tn2 2 r, r 3 .1.
Practise Now I 2. y= vx - -2vx+ e ' - I;
5 2 (e) -~J2- 7x+c
17. (i) S128 247.47 x' 7
(a) 4+c (b) ¾R+c - 1.83
(ii) 59090.9 1/year 3 +c
18. (i) 0.0808% Practise Now 2 Practise Now 10 (0 - 2J9-4x
(ii)-0.0120%/hour 2 I 16 +c
x , +c (b) 3x + c (a) Inx+c
(iii) 0.0920%
I. (a) -
9 4 (g) - 9(3x -l )'
1
19. (i) 2.5x sin(n - 0) cm' (c) I ax ' +c (b) In(Sx+3 ) +c 3
5
(ii) 1 (iii) 2JIS 2.
2
9</t' +c 3
(c) in (7 x+ l ) +c
(h)-- '
16(5-2x l' +c
An.S'"''C.1" Ktrs
E
204
J 12 r, 9 , 4. (a)
) l~•7
+c 3. 3_
(I) _ _ Review Exercise I 4
(d) :/ _s,ix · +2x · +c 2c 6x+I
I. (a) ii (2x +9 )' + c
(b)Be ' +c 7
(Ii) _.:!,ln-- + c 4
(<) x- 3
2 vx
" +(
(c) _!e -• +c
7 ,/6x+ I (b) - ,/5x-7 +c
9
(0 N7+4x +I 2l/X+c 4. (Ii) ¼sin2x+ c
(d) _ 404 _! e" +c
X
(c) 2tan +c
5
4 e5 ~ 5 10
9, r x+,+3 S. (a) 3 In x + c
5, (i) 4(2x - 5)' (7x +
(42x- 31)
1) 3
(d) _2,_...!._,in( rrx+5 )+ c
X 41'
2 , 7 ,
(b) - In (JO - x ) + c
10.ar 'jx •2·'" •4
9 (ii)¼(2x-5)' (7x+ I)' +c
I , S ,,.,
(e) x · + e +c
4 ,r. 16 (c) 4'n (4 x+ 7)+c 2 2
Jl, Y: 5 qx •s (d) -
4
1n (S -6x )+c
6. (i) Sx + !Ox In x (f) 3e' + 4e·• + C
3rr 6x
16. a;4, b; 4, c; 7 7. x = tant-t+ -I 10, (i) (ii)±
4 .j(3x- 2x' )'
17. (i) 4 8, (ii) y = _x_+2 " ') I .
cosx (111 x= , mm;
(ii))'; 2x' + 3x-8 (ii) 14x +c
I 3J3x-2x'
('") (-4,-98
lll 3 I) 9. y = -
4
4
cos2x+c
s_
IL (i) _3_ _ _ x= -
I
,max
!8. P; x' -4x' + 5x- 2500;
10, 3 x+2 2x-3 5. 1.10 units
54000 1 (ii) 2ln(x+2)- 2 r, !.,
II . (a) - -- + c ,Q
6. ~y= vx- -4e ' +5
lOe2xu 3
19.(a)~+c ;x> S
6 In(2x-3)+c 7. (i) a= 4, b = 3
(b) .!.e• • -e" +x+c 3
I O ~ (, 4 6 3 4
(ii) ~ + c
(b)
21 ,it3x+4 ) +
(c) - 2 e -•-• + I e ,._ , +c
12.(i) - 2
x+
3--1+--
x- (x-1)
,
4,/4x+3
3
~J(3x+4)' +c;x> -!
3 (d) _...!...+.!.e" +c 4
(ii) .:!,ln~--- + c 8. (ii) ¼x,/3x' + 7 +c
9x 4 5 x-1 5(x-I)
I 7x
Emcist l48 (e) .!.e•• _.!.e-• +c 13, (i) A = 6, B = -3 9
' (i) 2x-3+ 3x' +s
4 2
(ii)2=._ 6x
(a) 2.,in3x+!cos5x+c (t) e' +IOx-~+c x 2 +3
21 5 (ii) 3x'+5
e'
(b) ix' +2sinf+c
(iii) ln(2x+5)-
12. (a) 6,Jx+5lnx+c (iii) ½ln(2x-3)+
(c)-IOOcosO.Ix- ½in(x' +3)+c
I 2 I
0.QJ COS !Ox+ C ( b) x + Inx+c iln(3x 2 +5)+c
12 3 ") 6x+zsm
14, ( II I . 2 X+C
I
(d) 4tany+c (c) 4x+40lnx- IOO +c 10. (i) cotx
3sinx
(,) tan Bx+ c
X 15
' (ii) 7(I+cosx) +c (ii) 3lnsinx+
e'
(O 4 tanx+ c (d) 9x-6elnx--+c 4
X 16. (i) 6 cos' x - 3 J3cos,/3x+c
l. (a)y; x+!cos2x+J 1
13, (i) y= 2tan~+ ~ (ii) ftx+sinxcosxl+c
2 2 .,_,3 II. -lncosx+c
(b)y; x+!sin2x+~ (ii)0 17. (i) 3sinx-4sin 3 x;p=3 12. (i) 3x + 6x In 4x
4 4 andq=-4 I
(ii) x'(2ln4x-l)+c
. ( I0x- ") -
3. (a) 3co+ .. x )+c
(b)sin (nx + 2) + c
5 14, I sm
10 2 (ii)4elnx+¼cos3x-
4
13. ( 1') I x- I sm2x+c
.
I .!..sin2x+~x-.!..x 2 +c 9
cosx+c 2 4
(c) 5tan (Sx-9)+c
4 2 2 4 ") I x+ I s,n2x+c
.
18. 6 sec• x - 6 sec' x; ( 11
I 2 4
Exercise 14C
(d) 3tan(4+3xl+c 5 l (iii)x+ C
tan x+5tanx+c
I, (ii) xJ3x+I +c 3 1
14.(i) - -
3x+8 x 1nx
2, (i)
3 I
(ii)
J(3x+4 )
4 tnOnx)+c
("11 ) 4x
J3x+4 +c
p
Answe r Ke ys
205 E
8 Practise Now 9 Exercise I SB
15. (i) 5+-- 8 - (i) 2sec ' (2x-~)
2x-5
I. (i) 3 cos x - 3x sin x I. (i) 60x(5.r - 3)'
(ii) Increasing (ii)0.571 units' 4
(li)2 (ii) -665
(iii) Decreasing 9. (I) 0.457 (ii) 3
2. (ii)-'3+1 2. (ii)~
(iv) Sx + 4 In (2x _ 5) _ 9 9 IO. (ii) 0.5 (iii) 0.5 rn'
•.. )
dx
I ,
dx '
5
dx
Practise Now 12
4.5 units2 (ii) - IO 679 760.25 14. eh = -3, k= 32
(m y= x -lnx+ 15. (ii) 2+-3-.
3 3 8. (ii)4.47 x-2' 0 ·704 units
. '
Practise Now 13 9. (i) 4xe" (ii) 3e' + I 17. 1.25 units'
16 IO. (i) x + 2x In x - 3 18. (i) P(0, 4), Q(3, 3)
C hapter 15 Applications of (ii)7.34
Integration Practise Now 14 (ii) 6¼ units'
II. (i) 5x' + ISx' in x
Practise Now 1 I. 1.!. units2
¥
3 (ii)48.99 19· (.!.e• +1-.!.) units' ·
(a) (b) 10 2. (i) P(0, 17), Q(8.5, 0), R(3, 11) 3 a a '
12. (i) 4+.!. _ ( _)-
(ii) 45.25 units' x 2 x+3
(c) 158 3 [ ( I-; le"+;] units'
81 (iii)~
108 2(x-3)
Practise Now 2 (ii)4x+Jnx- 20. 17
(a) 78 (b) 37.8 Practise Now 15 3
1n[(x+3)(x-3)]+c;
2 Review Exercise 15
(i) P(I , I) (ii) ¾units' 2.98 64
Practise Now 3 I. (a) (b) 66.0
Exercise ISA 13. (iii) JJ-1-% 3
-ff
(a)
2 I (c) - (d) 34.1
(b) .!.
1. (a) 6
6 14. 4n+--
3"3
(b) +2-~ 2 (e) 0.566 (0 1.06
6
Practise Now 4
2 (c) 1905
7
(d)
3
I
15. (iii) 1 2. 4 or6
2 n 3n
(e) 3 (0 -;; 16. 4 cos 4x- 2 sin 4x 3.
1. (a) 19.09 (bl 20.09 2' T
123 17. (i) I
2. 1.108 (g) -~ (h) 4. (i) 2--s- (ii) 0.562
7 2 x+3
Exercise I 5C
Practise Now 5 Cil _I3 (j) -I I .
5. (i) 4xe2.ir
1
(ii) 22.3
I. (a) 21 units' 6. (i) I+ lnx (ii) 2.55
(a) 2.92 (b) 16.6
2. (a) -IO (b) _!_g 3
3 (b) 5.71 units' 7. (ii)0.143
Practise Now 6 (c) (d) 8 (c) 2.72 units' 3x 3 +4x 2 -4x+l
55 8. (i)
(a) -IO (bl 8 n' (d) 6.91 units' x'(l-2x)'
3. (a) (b) +1
4 2. (a) 5.21 units' (ii).!..!.
Practise Now 7
(c) I J3 n (b) 1.51 units'
8
1. (ii) 13.76 2 (d) 3+4-12 9. 2
(c) 0.386 units'
2. (i) 2xe'-'+ e'-' 4. (a) 1.19 (b) 0.781 10. 0.305
(d) 2.51 units' II. (i) P(4,8),Q(6,0)
(ii) .!.(e' +I ) (c) 39.4 (d) 86.9
2 3. 9 units'
(e) 11.7 (0 7.00 (ii)8: 19
3. (i) 3x + 6x In x
(g) 73.9 (h) -0.0754
4. (i) P(0, 15), Q(3, 9),
12. (i) PH, 4½ ), Q(2, 8),
(ii) 14.72
5. (a) 8.05 (b) 0.462 +½,o) R(4, 2)
(d) 5.16
Practise Now 8 (c) 2.08
(e) 0.472 (0 21.5
(ii) 12: 13
5. (a) (2-../2) units'
( "")
ll SuI units~
. ,
(i) ~ - - l -
2x+3 x+I
6. (a) 50 (b) -2 (b) units' 14. (i) ~+ln(2+xl
i
(ii) 6.85 2+x
7. W= .!.k(x'
2
- x') 6. units'
2 I
(ii) l--2-
8. 0.733 2+x
7. 1½ (iii) 7.621 units'
10. (i) -tan x (ii) ½ln2
15. (ii) 13.9 units'
16. 62
Answe,. Keys
E
206
p
8. (i) 0.405 minute 9. (i) 55 (ii) 33 s
y 0 urself
a,:all••&• (b) O
(ii) - 178 m/ min (Iii) 0.523 km
_ (a) 0 (iii) 56.1 m (Iv) a = 500e 20'
1
(c) O 9. (i) 1.6 1 s (ii) N o JO. (i) v = kn sec' nl,
a = 2kn' tan nl sec' nl
2- ~units' 10. 8" s
1 I. (i) 5.85 mis; -0.0685 m is'
J. 4-4.9 11. (i) No (ii) m/s (iii) 14.5 m
12. a p =2, q =-4, r = 2
_,!M1Hiil¥ Exerci se 16B
Challenge Yourself
I. (ii)39 m
practist Now I
(ii) 42 mis' I. (i) s = -t' +13 t' +I01 + 4
(i) J6rn/S
(iv) 8.5 m (ii) 9.04 (iii) 254 m
(iil) I or 1.5 Chapter 17 Proofs in Plane
(iv) 250 m Geomctq
M sm
practist Now 2
2. (i) T m (ii) 6 s Practise Now 3
3. (i) 8.5 m is (ii) 0 2. (ii) 6 ADR, 6 CQD
(i) 6.5J cm .
4. (i) 4 or 6 (ii) 36 m (iii) 6 QCP
(ii) v=3 + Scos 2t;a = -16 sin 21
(iii)36cm (iv) 2i cm
9. (i) 0.408
(iii) 24.4 m/s
(ii) 17.9m
Revision Exercise Fl
Practise Now 6 10. h =-2, k = 12
I. (a) 0.183 (b) 4.49
(il)2.70m 11 (ii) 860 m
. 3 2. (ii) _g
12. (i) 7 m / s (iii) 8 3
Exercise 16A 5
(iv) 31.5 m 3. ( i i ) - --
I. (i) 133 emfs (ii) 2 em fs' 2(x+2)2
(iii) 11 (iv) 452 cm 4. (i) a = 9, b = 16
Review Exercise 16
(v) 452 cm
I. (i) 4 (ii) I.SI m (ii)y= 9x+~-10
2. (i) v=6t' - 6t - 12;a= 121-6 X
10
(ii)2 2. (i)
27
mis (iii) 5m 5. (i) A(3, O) (ii) ~o units'
(iii) -13.5 m/s 3. (i) -2.94 mis' (iii) No
3. (i) 24 s, -576 cm/s (iii) 5.42 m 2 0
6. (i) ~ m
(ii)2048cm 4. (i) 1 h
(ii) 15 s, -37.5 mis
4. (i) -5 mis (ii) 4 s, -45 mis 5. (i) V= 312 - 201 + 25;
(iii) 100m a= 61- 20
Revision Exercise F2
5. (i) 3.29m (ii)5m (iii) 5
1000 1. (a) 53 (b) 0.428
(ii)v = ( 2-
3
°;2) mis, (iv) } or 5 (v) n m
2. y = -x' + 2x' + X - 7
9.,fi_
6. (i) b = -24, c = ½ 3. (ii) a = -¾, b ¼, c
= = ¾
a= --2- mis' (ii)-22.5 mis; 3 mis'
(iii) 0.243 minutes 4. (i) -1 (ii) 2
6. (i) 4m 7. (i) t, = ~.l, =7 ···> 628 umts
(ii) 3 mis (m 81
. 2
C A nswer Ke )'S
207 E