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# Test IGCSE Class XII Part II

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Use the trapezium rule with three intervals to estimate the value of
&Oacute;
10
2
0
ln 1 + sin x dx,
giving your answer correct to 2 decimal places.
2
3
4

Using the substitution u = 4x , solve the equation 4x + 42 = 4x+2 , giving your answer correct to
3 significant figures.

A curve has equation y = cos x cos 2x. Find the x-coordinate of the stationary point on the curve in

the interval 0 &lt; x &lt; 12 0, giving your answer correct to 3 significant figures.
(i) Express 3 sin 1 + 2 cos 1 in the form R sin 1 + !, where R &gt; 0 and 0&Aring; &lt; ! &lt; 90&Aring;, stating the exact

value of R and giving the value of ! correct to 2 decimal places.
(ii) Hence solve the equation
for 0&Aring; &lt; 1 &lt; 180&Aring;.
3 sin 1 + 2 cos 1 = 1,

5
A
r
O
2x rad
T
B
The diagram shows a circle with centre O and radius r. The tangents to the circle at the points A and
B meet at T , and the angle AOB is 2x radians. The shaded region is bounded by the tangents AT and
BT , and by the minor arc AB. The perimeter of the shaded region is equal to the circumference of the
circle.
(i) Show that x satisfies the equation
tan x = 0 − x.
3
(ii) This equation has one root in the interval 0 &lt; x &lt; 12 0. Verify by calculation that this root lies
between 1 and 1.3.

(iii) Use the iterative formula
xn+1 = tan−1 0 − xn to determine the root correct to 2 decimal places. Give the result of each iteration to 4 decimal
places.

6
Let I = &Ocirc;
1
0
x
dx.
2− x
(i) Using the substitution u = 2 − x, show that I = &Ocirc;
2
1
2 2 − u2
du.
u

(ii) Hence show that I = 8 ln 2 − 5.
7

The complex number u is given by u = −1 + 4&iuml;3i.
(i) Without using a calculator and showing all your working, find the two square roots of u. Give

your answers in the form a + ib, where the real numbers a and b are exact.
(ii) On an Argand diagram, sketch the locus of points representing complex numbers &Iuml; satisfying

the relation &Iuml; − u = 1. Determine the greatest value of arg &Iuml; for points on this locus.
8
Let f x =
5x2 + x + 6
.
3 − 2x x2 + 4
(i) Express f x in partial fractions.

(ii) Hence obtain the expansion of f x in ascending powers of x, up to and including the term in x2 .

9
The number of organisms in a population at time t is denoted by x. Treating x as a continuous variable,
the differential equation satisfied by x and t is
xe−t
dx
,
=
dt
k + e−t
where k is a positive constant.
(i) Given that x = 10 when t = 0, solve the differential equation, obtaining a relation between x, k
and t.

(ii) Given also that x = 20 when t = 1, show that k = 1 −
2
.
e

(iii) Show that the number of organisms never reaches 48, however large t becomes.

1
Solve the inequality | x − 2| &gt; 3|2x + 1|.

2
Solve, correct to 3 significant figures, the equation
ex + e2x = e3x .
3
N
D
C
r
a
A

x
3a
M
B
In the diagram, ABCD is a rectangle with AB = 3a and AD = a. A circular arc, with centre A and
radius r, joins points M and N on AB and CD respectively. The angle MAN is x radians. The
perimeter of the sector AMN is equal to half the perimeter of the rectangle.
(i) Show that x satisfies the equation
sin x = 14 (2 + x).

(ii) This equation has only one root in the interval 0 &lt; x &lt; 12 π . Use the iterative formula
xn+1 = sin−1 2 + xn
4
,
with initial value x1 = 0.8, to determine the root correct to 2 decimal places. Give the result of
each iteration to 4 decimal places.

4
(i) Show that the equation tan(30◦ + θ ) = 2 tan(60◦ − θ ) can be written in the form
√
tan2 θ + (6 3) tan θ − 5 = 0.

(ii) Hence, or otherwise, solve the equation
tan(30◦ + θ ) = 2 tan(60◦ − θ ),
5
for 0◦ ≤ θ ≤ 180◦ .
The variable complex number is given by

= 2 cos θ + i(1 − 2 sin θ ),
where θ takes all values in the interval −π &lt; θ ≤ π .
(i) Show that | − i| = 2, for all values of θ . Hence sketch, in an Argand diagram, the locus of the

point representing .
(ii) Prove that the real part of
1
is constant for −π &lt; θ &lt; π .
+2−i

6
The equation of a curve is xy(x + y) = 2a3 , where a is a non-zero constant. Show that there is only
one point on the curve at which the tangent is parallel to the x-axis, and find the coordinates of this
point.

7
Let f(x) ≡
x2 + 3x + 3
.
(x + 1)(x + 3)
(i) Express f(x) in partial fractions.

3
(ii) Hence show that f(x) dx = 3 − 12 ln 2.
0

8
y
P
O
N
T
1
2p
x
In the diagram the tangent to a curve at a general point P with coordinates (x, y) meets the x-axis at T .
The point N on the x-axis is such that PN is perpendicular to the x-axis. The curve is such that, for all
values of x in the interval 0 &lt; x &lt; 12 π , the area of triangle PTN is equal to tan x, where x is in radians.
(i) Using the fact that the gradient of the curve at P is
PN
, show that
TN
dy 1 2
= y cot x.

dx 2
(ii) Given that y = 2 when x = 16 π , solve this differential equation to find the equation of the curve,
expressing y in terms of x.

y
9
M
R
x
O
−1x √
The diagram shows the curve y = e 2 (1 + 2x) and its maximum point M . The shaded region between
the curve and the axes is denoted by R.
(i) Find the x-coordinate of M .

(ii) Find by integration the volume of the solid obtained when R is rotated completely about the
x-axis. Give your answer in terms of π and e.

10
The points A and B have position vectors, relative to the origin O, given by
−−→
OA = i + 2j + 3k
and
−−→
OB = 2i + j + 3k.
The line l has vector equation
r = (1 − 2t)i + (5 + t)j + (2 − t)k.
(i) Show that l does not intersect the line passing through A and B.

(ii) The point P lies on l and is such that angle PAB is equal to 60◦ . Given that the position vector
of P is (1 − 2t)i + (5 + t)j + (2 − t)k, show that 3t2 + 7t + 2 = 0. Hence find the only possible

position vector of P.
1
In a certain country 12% of houses have solar heating. 19 houses are chosen at random. Find the
probability that fewer than 4 houses have solar heating.

2
A school club has members from 3 different year-groups: Year 1, Year 2 and Year 3. There are 7
members from Year 1, 2 members from Year 2 and 2 members from Year 3. Five members of the
club are selected. Find the number of possible selections that include at least one member from each
year-group.

3
Roger and Andy play a tennis match in which the first person to win two sets wins the match. The
probability that Roger wins the first set is 0.6. For sets after the first, the probability that Roger wins
the set is 0.7 if he won the previous set, and is 0.25 if he lost the previous set. No set is drawn.
(i) Find the probability that there is a winner of the match after exactly two sets.

(ii) Find the probability that Andy wins the match given that there is a winner of the match after
exactly two sets.

4
Coin A is weighted so that the probability of throwing a head is 23 . Coin B is weighted so that the
probability of throwing a head is 41 . Coin A is thrown twice and coin B is thrown once.
(i) Show that the probability of obtaining exactly 1 head and 2 tails is
5
6
13 .
36

(ii) Draw up the probability distribution table for the number of heads obtained.

(iii) Find the expectation of the number of heads obtained.

Find how many different numbers can be made from some or all of the digits of the number 1 345 789
if
(i) all seven digits are used, the odd digits are all together and no digits are repeated,

(ii) the numbers made are even numbers between 3000 and 5000, and no digits are repeated,

(iii) the numbers made are multiples of 5 which are less than 1000, and digits can be repeated. 
The times taken by 57 athletes to run 100 metres are summarised in the following cumulative frequency
table.
Time (seconds)
Cumulative frequency
&lt; 10.0
0
&lt; 10.5
4
&lt; 11.0
10
&lt; 12.0
40
&lt; 12.5
49
&lt; 13.5
57
(i) State how many athletes ran 100 metres in a time between 10.5 and 11.0 seconds.

(ii) Draw a histogram on graph paper to represent the times taken by these athletes to run 100 metres.

(iii) Calculate estimates of the mean and variance of the times taken by these athletes.
7

The time Rafa spends on his homework each day in term-time has a normal distribution with mean
1.9 hours and standard deviation 3 hours. On 80% of these days he spends more than 1.35 hours on
his homework.
(i) Find the value of 3 .

(ii) Find the probability that, on a randomly chosen day in term-time, Rafa spends less than 2 hours
on his homework.

(iii) A random sample of 200 days in term-time is taken. Use an approximation to find the probability
that the number of days on which Rafa spends more than 1.35 hours on his homework is between
163 and 173 inclusive.

1
Some adults and some children each tried to estimate, without using a watch, the number of seconds
that had elapsed in a fixed time-interval. Their estimates are shown below.
Adults:
Children:
2
55
86
58
95
67
89
74
72
63
61
61
84
63
77
71
92
56
81
53
54
54
43
78
68
73
62
64
67
62
83
(i) Draw a back-to-back stem-and-leaf diagram to represent the data.

(ii) Make two comparisons between the estimates of the adults and the children.

There is a probability of
chosen at random.
1
7
that Wenjie goes out with her friends on any particular day. 252 days are
(i) Use a normal approximation to find the probability that the number of days on which Wenjie
goes out with her friends is less than than 30 or more than 44.

(ii) Give a reason why the use of a normal approximation is justified.
3
A pet shop has 6 rabbits and 3 hamsters. 5 of these pets are chosen at random. The random variable
X represents the number of hamsters chosen.
(i) Show that the probability that exactly 2 hamsters are chosen is
4
10 .
21
7

(ii) Find Σ x2 for the original group of 28 people. Hence find the standard deviation of the heights of
the remaining group of 27 people.

When Moses makes a phone call, the amount of time that the call takes has a normal distribution with
mean 6.5 minutes and standard deviation 1.76 minutes.
(i) 90% of Moses’s phone calls take longer than t minutes. Find the value of t.
6

(ii) Draw up the probability distribution table for X .

The heights, x cm, of a group of 28 people were measured. The mean height was found to be 172.6 cm
and the standard deviation was found to be 4.58 cm. A person whose height was 161.8 cm left the
group.
(i) Find the mean height of the remaining group of 27 people.
5


(ii) Find the probability that, in a random sample of 9 phone calls made by Moses, more than 7 take
a time which is within 1 standard deviation of the mean.

Tom and Ben play a game repeatedly. The probability that Tom wins any game is 0.3. Each game is
won by either Tom or Ben. Tom and Ben stop playing when one of them (to be called the champion)
has won two games.
(i) Find the probability that Ben becomes the champion after playing exactly 2 games.

(ii) Find the probability that Ben becomes the champion.

(iii) Given that Tom becomes the champion, find the probability that he won the 2nd game.
Nine cards are numbered 1, 2, 2, 3, 3, 4, 6, 6, 6.

(i) All nine cards are placed in a line, making a 9-digit number. Find how many different 9-digit
numbers can be made in this way
(a) if the even digits are all together,

(b) if the first and last digits are both odd.

(ii) Three of the nine cards are chosen and placed in a line, making a 3-digit number. Find how
many different numbers can be made in this way
(a) if there are no repeated digits,

(b) if the number is between 200 and 300.

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