738 ANSWERS

hi ii 3

iii y=1

8 If x=^12 , (¡2)

(^12)

p
¡ 2 which is undefined.
9aP=^400
5 t
b M=^216
3 x
EXERCISE 28C.1
1ax=1 bx=2 c x=3 dx=0
ex=¡ 1 fx=¡ 1 gx=¡ 4 hx=0
i x=¡ 4 j x=¡ 2 kx=6 l x=2
m x=¡^34 nx=^72 ox=0 px=4
2ax=3 bx=0 c x=¡ 2 dx=3
ex=3 fx=¡ 2 gx=^27 hx=^13
i x=1 j x=1 kno solution l x=3or¡ 1
3 a=6,n=2 4 b=^14 ,t=5 5 x=¡ 1 ,y=2
EXERCISE 28C.2
1ax¼ 6 : 644 bx¼¡ 1 : 884 cno solution exists
dx¼ 1 : 292 e x¼¡ 1 : 611 f x¼ 4 : 192
gx¼¡ 4 : 583 h x¼¡ 1 : 848 i x¼¡ 4 : 858
j x¼ 2 : 064 k x¼ 2 : 991 l x¼ 291 : 825
m x¼ 0 : 262 n x¼ 1 : 441 ox¼ 0 : 415
EXERCISE 28D
1a 40 mongooses
bi¼ 61
ii¼ 160
iii 2560
d¼ 6 : 61 years
c
2a 50 echidnas
bi 100
ii 400
iii ¼ 5080
d¼ 4 : 75 years
c
3aG 0 =28
bi¼ 39
ii¼ 86
iii ¼ 822
d¼ 17 : 5 years
c
4a 2 : 3 grams
bi 1 : 00 grams ii 0 :000 562grams
iii 1 : 73 £ 10 ¡^36 grams
c
d 56 :5% e¼ 25 : 4 years
5a 100 oC
bi 70 : 7 oC
ii 17 : 7 oC
iii 0 :003 05oC
d ¼ 4 : 12 minutes
c
6a$5800
bi$7367: 38 ii $12 873: 97 iii¼ 8 : 69 years
7a$500 bi$445: 64 ii$199: 11
c ¼ 62 : 8 months¼ 5 years 3 months
8aB¼ 20 £ 2
23 d
ci¼ 50
ii¼ 508
iii ¼12 900
d ¼ 11 : 9 days
b
9a i$ 6 : 42 million
ii$ 52 : 4 million
c ¼ 6 : 33 years
b
EXERCISE 28E
1aP¼ 25 :1(1:32)x b N¼ 5 :70(0:815)t
2aYes, very well. V¼216 000(1:023)t
bi¼E237 000 ii¼E266 000
c The 2004 figure is reliable as it is between the polest=0
and t=8. For this reason, the 2009 figure may not be
reliable.
3aThe fit is excellent asr^2 ¼ 1. C¼300(0:3487)t
b ¼ 1312 minutes
REVIEW SET 28A
1a 5
(^12)
b 7 ¡
(^13)
c 51
(^14)
d 47 ¡
(^15)
2a 8 b 25 c 271 d^18
3a i 5 ¡x
ii¡ 5 x
iii 2 £ 5 x
iv 52 x
b
3
y¡=¡1
y
O x
f(x)= 2 ( 3 - x)+ 1
5 10 15 20 t
5000
4000
3000
2000
1000
P
P= 50 ́ 23 t
50
t
50 100 150 200
2.5
2
1.5
1
0.5
W
2.3
W= 2. 3 ́ 2 -^0.^06 t
t
10 20 30 40 50 60
100
80
60
40
20
T
T= 100 ́ 2 -^4 t
10 20 30 n
2500
2000
1500
1000
500
P
P= 40 ́ 20.^2 n
40
O
n
5 10 15 20 25 30
1000
800
600
400
200
G
28
G= 28 ́ 50.^07 n
O
3.8
F
O n
F= 3. 8 ́( 1. 3 )n
20
B
O d
d
B 20 23
2
= ́
y
x
22
11
yx¡=¡¦()
yx¡=¡-¦()
yx¡=¡¦(- )
yx¡=¡2¦()
yx¡=¡¦(2 )
O
IB MYP_3 ANS
cyan magenta yellow black
(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_an\738IB_IGC1_an.CDR Thursday, 20 November 2008 12:14:07 PM PETER