Mathematics I - Unit Wise Questions
1. Circle(O) the correct answer.
i) If A ={ x : x is a triangle}, B = {x : x is an isosceles triangle} and C = {x : x is an equilateral triangle}then,
a) A ⊂ B ⊂ C b) C ⊂ B ⊂ A c) B ⊂ C ⊂ A d) B ⊂ A ⊂ C
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1.
ii) If and g(x) = x + 1 then, what is the value of gof( x)?
(b)
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1.
i) If A = [-1,3) and B = [2,5], then A-B is equal to
a) [-1,2) b) [-1,3) c) (-1,2) d) [-1,3]
(a)
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1. In class of 100 students 40 students failed in Mathematics, 70 failed in English and 20 failed in both subjects. Find
a) How many students passed in both subjects?
b) How many students passed in Mathematics only?
c) How many students failed in mathematics only?
Let M and E be the set of students who failed in Mathematics and English respectively.
Then,
n(U) = 100
n(M) = 40
n(E) = 70
n(M∩E) = 20
i) We have,
Therefore, number of students passed in both subjects = 10.
ii)
Number of students passed in Mathematics only =
iii)
Number of students failed in mathematics only = n(M) - n(M∩E) = 40 - 20 = 20
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2. Find the domain and range of the function
Given,
For domain; when (3-x)=0, f(x) doesn't exist, it means f(x) is exist for all real number except x = 3. Therefore domain is
For range,
Let,
i.e.
Here, x is exist for all real number except y = -2. Therefore range is
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1 ii) If A, G, H are the Arithmetic mean, Geometric mean and Harmonic mean between two positive numbers then,
a) A < G < H b)A > H > G c) G < A < H d) A > G > H
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1.
iii) What is the reciprocal of the complex number (2,1)?
a) (1/5, 1/5) b) (2/5, -1/5) c) (-2/5, 1/5) d) (-2, -1)
(b)
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3. Find the Maclurin series of the function f(x) = sinx.
Maclaurin series for a function f(x) is found by:
So, we need to find derivatives of
Thus, the Maclaurin series for sin(x) is
Simplifying this yields the following:
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1 iii) Range of the function is,
a)(-2 , 2) b)[-2, 2) c) [-2, 2] d) (-2, 2]
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1.
iv) What type of function y = f(x) = ax2 + bx + c is?
a) Constant function b) Linear function c) Identity function d) Quadratic function
(d)
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4. Prove that = (x - y) (y - z) (z - x).
Given
Applying,
Hence proved.
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1 iv) The sum of the series given by is equal to
a) e - 2 b) e c) e - 1 d)
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1.
v) Geometrical meaning of scalar triple product of three vectors is the
a) Volume of parallelepiped formed by as adjacent sides
b) x Projection of
on
and
c) x Projection of
on
d)
(a)
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1 v) If the order of matrix A is m x n and order of matrix B is n x m, then the order of the matrix AB is,
a) n x n b) m x n c) n x m d) m x m
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5. Find a unit vector perpendicular to the plane containing points P(1, -1, 0), Q(2, 1, -1) and R(-1, 1, 2).
The given points P(1, -1, 0), Q(2, 1, -1) and R(-1, 1, 2) lies in the plane PQR.
Accordingly, the vectors the plane PQR.
Hence, plane PQR.
Finally, the required unit vector will be
Finally, the desired unit vector is
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1 vi) Length of the Latus rectum of the parabola 2y2 - 9x = 0 is,
a) b)
c)
d)
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1.
vi) If a, b, c is in H.P then, what is the value of b?
(c)
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6. In how many ways can be letter of words “Sunday” be arranged? How many of these arrangement begin with S? How many begin with S and don’t end with y?
The word SUNDAY be arranged in 6!=6*5*4*3*2=720 ways
When a word begins with S. Its position is fixed, i.e. the first position. Now rest 5 letters are to be arranged in 5 places. So,
No. of arrangement begin with S = 5! = 120
The are 5! ways of ordering the word SUNDAY if the first letter is restricted to S, because only the 5 remaining ones are allowed to change.
There are 4! ways of ordering the word SUNDAY if the first letter is restricted to S "and" the last letter is restricted to Y
Therefore, there are 5!-4! ways that the word SUNDAY can be arranged such that the first letter is S and the last letter "is not" Y
5!-4! = 120-24 =96
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7. If then show that x2 + y2 = 1.
Given,
Now,
Multiplying eqn. (i) & (ii)
Hence proved.
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1 vii) Which of the following statement is not true?
a) is a vector b)
is a vector
c) is a vector c)
is a vector
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1.
vii) Which of the following is the rank of the Matrix ?
a) 0 b) 1 c) 2 d) 3
(b)
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1 viii) How many triangles can be formed by joining six non-collinear points.
a) 80 b) 40 c)160 d)240
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1.
viii) In how many ways 6 persons can seat in a round table?
a) 720 b) 360 c) 120 d) 60
(a)
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1.
ix) Let , and a map
defined by T(x)=A(x) then what is the image of
under T?
(a)
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1 ix) Real part of the complex number is,
a) b)
c) 2 d)
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8. a) Define conic section. Find the coordinates of vertices, eccentricity and foci of the ellipse
9x2 + 4y2 - 18x - 16y - 11 = 0. (1+5)
A conic section (or simply conic) is a curve obtained as the intersection of the surface of a cone with a plane. The three types of conic sections are the hyperbola, the parabola, and the ellipse.
Given ellipse,
9x2 + 4y2 - 18x - 16y - 11 = 0
Converting to standard form of ellipse:
Here, h=1, k=2, a=2, b=3
Now,
Coordinate of Vertices:
i.e. (1, 5) & (1, -1)
Eccentricity:
Foci:
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1.
x) If then, this is the equation of..
a) Parabola b) Hyperbola c) Ellipse d) Circle
(a)
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x) If S1 is the sum of first n natural numbers and S2 is the sum of cubes of first n numbers then,
a) S1 = b)
= S2 c)S1 = 3S2 d) S2 =
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b) If T(x1, x2) = (x1 + x2, x2, x1)defined by be the linear transformation, then find matrix associated with linear map T. (4)
Given,
T(x1, x2) = (x1 + x2, x2, x1)
We have,
T(e1) = T(1, 0) = (1+0, 0, 1) = (1, 0, 1)
T(e2) = T(0, 1) = (0+1, 1, 0) = (1, 1, 0)
Hence
A = |T(e1), T(e2)|
=
We confirm
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9. a) Define irrational number. Prove that √2 is an irrational number. (1+4)
An irrational number is a number that cannot be expressed as a fraction for any integers
and
.
Let us assume on the contrary that is a rational number. Then, there exist positive integers p and q such that
, where, p and q, are co-prime i.e. their is
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b) If functions defined by f(x) = 2x + 1 and
defined by g(x) = x2 - 2. Find the formulae for composite functions
and also verify that
(4+1)
Given,
f(x) = 2x + 1
g(x) = x2 - 2
Now,
fog(x) = f(g(x)) = 2(x2 - 2)+1
= 2x2-4+1
= 2x2-3
gof(x) = g(f(x)) = (2x+1)2-2
= 4x2+4x-1
Hence,
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10. a) If arithmetic mean, geometric mean and harmonic mean between two unequal positive numbers are A, G, H respectively. Then prove that A > G > H. (4)
Let and be two real positive and unequal numbers and let be arithmetic, geometric and harmonic mean respectively then,
A =
G =
H =
Now,
A - G =
A - G > 0 i.e. A>G
Again,
G - H =
G - H > 0 i.e. G>H
Hence proved that
A > G > H
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b) What is the relation between permutation and combination of n objects taken r at a time? A committee of 5 is to be constituted from 6 boys and 5 girls. In how many ways can this be done so as to include at least a boy and a girl? (1+5)
The relation between permutation and combination of n objects taken r at a time is derived as:
Now,
Total no. of students required to be chosen = 5
No. of boys = 6
No. of girls = 5
Total no. of ways to choose 5 students out of 11
students = 11C5 =
The case where all committee has boys = 6C5
= 6
The case where all committee has girls = 5C5 =1
Therefore, The number of ways when at least1 boy and 1 girls are in
committee = 462-(6+1) = 455 ways
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