Use the Factor Theorem to determine whether g(x) is a factor of p(x) in each of the following cases:(i) p(x) = 2x 3 + x 2 – 2x – 1, g(x) = x + 1(ii) p(x) = x 3 + 3x 2 + 3x + 1, g(x) = x + 2(iii) p(x) = x 3 – 4x 2 + x + 6, g(x) = x – 3
Find the value of k, if x – 1 is a factor of p(x) in each of the following cases:
(i) p(x) = x 2 + x + k
(ii) p(x) = 2x 2 + kx +√2
(iii) p(x) = kx2 – \(\sqrt{2x}\) + 1
(iv) p(x) = kx2 – 3x + k
Use suitable identities to find the following products:
(i) (x + 4) (x + 10)
(ii) (x + 8) (x – 10)
(iii) (3x + 4) (3x – 5)
(iv) \((y^ 2 + \frac{3 }{ 2}) (y^ 2 – \frac{3 }{ 2}) \)
(v) (3 – 2x) (3 + 2x)
Evaluate the following products without multiplying directly:
(i) 103 × 107 (ii) 95 × 96 (iii) 104 × 96
Factorise the following using appropriate identities:
(i) 9x 2 + 6xy + y 2
(ii) 4y 2 – 4y + 1
(iii) x 2 – \(\frac{y^2 }{ 100}\)
Expand each of the following, using suitable identities:
(i) (x + 2y + 4z) 2 (ii) (2x – y + z) 2 (iii) (–2x + 3y + 2z) 2
(iv) (3a – 7b – c) 2 (v) (–2x + 5y – 3z) 2 (vi) [ \(\frac{1 }{ 4}\) a - \(\frac{1 }{ 2}\) b + 1]2
Write the coefficients of x 2 in each of the following:
(i) 2 + x 2 + x
(ii) 2 – x 2 + x 3
(iii) \(\frac{π }{ 2}\) x2 + x
(iv) √2 x -1
Find the value of the polynomial 5x – 4x 2 + 3 at
(i) x = 0 (ii) x = –1 (iii) x = 2
Factorise:
(i) 4x 2 + 9y 2 + 16z 2 + 12xy – 24yz – 16xz
(ii) 2x 2 + y 2 + 8z 2 – 2√2 xy + 4√2 yz – 8xz
Write the following cubes in expanded form:
(i) (2x + 1)3 (ii) (2a – 3b) 3 (iii) [\(\frac{3}{2}\) x + 1]3 (iv) [x - \(\frac{2 }{ 3} \)y]3
Factorise each of the following:
(i) 8a 3 + b 3 + 12a 2b + 6ab2
(ii) 8a 3 – b 3 – 12a 2b + 6ab2
(iii) 27 – 125a 3 – 135a + 225a 2
(iv) 64a 3 – 27b 3 – 144a 2b + 108ab2
(v) 27p 3 – \(\frac{1}{ 216}\) – \(\frac{9 }{ 2}\) p2 + \(\frac{1 }{4}\) p
(i) 27y 3 + 125z 3
(ii) 64m3 – 343n 3
[ Hint : See Question 9. ]
The following frequency distribution gives the monthly consumption of electricity of 68 consumers of a locality. Find the median, mean and mode of the data and compare them
Monthly consumption (in units)
Number of consumers
65 - 85
4
85 - 105
5
105 - 125
13
125 - 145
20
145 - 165
14
165 - 185
8
185 - 205
Class interval
Frequency
0 - 10
10 - 20
x
20 - 30
30 - 40
15
40 - 50
y
50 - 60
Total
60
A life insurance agent found the following data for distribution of ages of 100 policy holders. Calculate the median age, if policies are given only to persons having age 18 years onwards but less than 60 year.
Age (in years)
Number of policy holders
Below 20
2
Below 25
6
Below 30
24
Below 35
45
Below 40
78
Below 45
89
Below 50
92
Below 55
98
Below 60
100
The lengths of 40 leaves of a plant are measured correct to the nearest millimetre, and the data obtained is represented in the following table :
Length (in mm)
Number of leaves
118 - 126
3
127 - 135
136 - 144
9
145 - 153
12
154 - 162
163 - 171
172 - 180
Find the median length of the leaves. (Hint : The data needs to be converted to continuous classes for finding the median, since the formula assumes continuous classes. The classes then change to 117.5 - 126.5, 126.5 - 135.5, . . ., 171.5 - 180.5.)
The following table gives the distribution of the life time of 400 neon lamps :
1500 - 2000
2000 - 2500
56
2500 - 3000
3000 - 3500
86
3500 - 4000
74
4000 - 4500
62
4500 - 5000
48
Find the median life time of a lamp.
100 surnames were randomly picked up from a local telephone directory and the frequency distribution of the number of letters in the English alphabets in the surnames was obtained as follows:
Number of letters
1 - 4
4 - 7
7 - 10
10 - 13
13 - 16
16 - 19
Number of surnames
30
40
16
Determine the median number of letters in the surnames. Find the mean number of letters in the surnames? Also, find the modal size of the surnames.
The distribution below gives the weights of 30 students of a class. Find the median weight of the students.
40 - 45
45 - 50
50 - 55
65 - 60
70- 65
65 - 70
70 - 75
A student noted the number of cars passing through a spot on a road for 100 periods each of 3 minutes and summarised it in the table given below. Find the mode of the data :
The given distribution shows the number of runs scored by some top batsmen of the world in one-day international cricket matches.
3000 - 4000
4000 - 5000
18
5000 - 6000
6000 - 7000
7
7000 - 8000
8000 - 9000
9000 - 10000
1
10000 - 11000
Find the mode of the data.