AIEEE Mathematics 2008
Mathematics 2008
Statement-1:
r is equivalent to either q or p .
Statement 2:
r is equivalent to ~(p ~q)
(1) Statement -1 is true , Statement -2 is false
(2) Statement -1 is false, Statement -2 is true
(3) Statement -1 is true, Statement -2 is true:
Statement -2 is a correct explanation for
Statement -1
(4) Statement -1 is true, Statement -2 is true:
Statement -2 is not a correct explanation for
Statement -1
Statement -1 :
The number of different ways the child can buy the six ice-creams is .
Statement -2 :
The number of different ways the child can buy the six ice-creams is equal of different ways of arranging 6 A’s and 4 B’s in a row
(1) Statement -1 is true, Statement -2 is false
(2) Statement -1 is false, Statement -2 is true
(3) Statement -1 is true , Statement -2 is true
Statement -2 is a correct explanation for Statement -1
(4) Statement -1 is true , Statement-2 is true :
Statement -2 is not a correct explanation for Statement -1
x1+ x2+ x3+ x4+ x5 = 6
=> statement (1) is false but statement (2) is correct.
(1) Statement -1 is true, Statement -2 is false
(2) Statement -1 is false, Statement -2 is true
(3) Statement -1 is true, Statement -2 is true
Statement -2 is a correct explanation for Statement -1
(4) Statement -1 is true, Statement-2 is true :
Statement -2 is not a correct explanation for Statement -1
Ans.
(1) Statement -1 is true, Statement -2 is false
(2) Statement -1 is false, Statement -2 is true
(3) Statement -1 is true, Statement -2 is true
Statement -2 is a correct explanation for Statement -1
(4 Statement -1 is true, Statement-2 is true :
Statement -2 is not a correct explanation for Statement -1
Ans.
statement 1 is correct
Statement -1 :
If A 1 and A- 1 , then A = - 1
Statement- 2:
If A 1 and A - 1, then tr (A) 0.
(1) Statement -1 is true, Statement -2 is false
(2) Statement -1 is false, Statement -2 is true
(3) Statement -1 is true, Statement -2 is true
Statement -2 is a correct explanation for Statement -1
(4) Statement -1 is true, Statement-2 is true :
Statement -2 is not a correct explanation for Statement -1
(1) 5 (2) 7 (3) 1 (4) 3
Ans.
= Oscillating between -1 & 1
=> RHD does not exists
Non diff. At x=1
(1) 4
(2) –4
(3) –12
(4) 12
br2 + br3 = 48 r<0
b(1+r) = 12 & br2 (1+r) = 48
Divide => r2 = 4 =>
As r<0, we take r = -2
Replace r in (1) to get
Arrange M|||PP| in
Between 7 letter there are 8 possibilities for 4
(1) (2, 0)
(2) (0, 2)
(3) (1, 0)
(4) (0, 1)
Ans.
distance of vertex from directrix = distance from focus => V=(1, 0) 22. The point diametrically opposite to the point P(1, 0) on the circle x2 + y2 + 2x + 4y – 3 = 0 is
(1) (3, 4)
(2) (3, -4)
(3) (-3, 4)
(4) (-3, -4)
satisfying the condition y(1) = 1 is
(1) y = x ln x + x
(2) y = ln x + x
(3) y = x ln x x + x2
(4) y = x e(x-1)
Ans.
(1) 1
(2) 2
(3) –1
(4) 0
Ans. x - cy - bz = 0cx - y + az = 0
bx + ay - z = 0
It is given that system of equations is consistent.
i.e. posses a solution.
It is given that not all x, y, z are zero.
=> Non trivial solution exist
=> D = 0
Evalute 1(-1 - a2) + c(-c - ab) - b(ac + b) = 0
=>-1 - a2 - c2 - abc - abc - b2 = 0
=> a2 + b2 + c2 + 2abc = -1
26. Let A be a square matrix all of whose entries are integers. Then which one of the following is true ?
(1) If det A = , then A-1 need not exist
(2) If det A = , then A-1 exists but all its entries are not necessarily integers
(3) If det A , then A-1 exists and all its entries are non-integers.
(4) If det A = , then A-1 exists and all its entries are integers
Ans. For example, let
det(A) = 1
A-1 exists & all entries are integers.
27. The quadratic equations x2 – 6x + a = 0 and x2 – cx + 6 = 0have one root in common. The other roots of the first and second equations are integers in the ration 4: 3. Then the common root is
(1) 2 (2) 1
(3) 4 (4) 3
Ans.
(1) a = 3, b = 4
(2) a = 0, b = 7
(3) a = 5, b = 2
(4) a = 1, b = 6
Ans.simplify (1) to get:
23 + a + b=30 => a + b = 7 -----(3)
simplify (2) to get
(a - 6)2 + (b - 6)2 + 4 + 1 + 16=34
=> (a - 6)2 + (7- a - 6)2 = 13
(a2-12a + 36) + (a2 +1 - 2a) = 13
2a2-14a + 24 = 0
a2 - 7a +12 = 0 => (a-4) (a-3) = 0 => b = 3, or 4
29. The vector lies in the plane of the vectors and and bisects the angle between Then which one of the following gives possible values of
(1) a = 8, b = 2
(2) a = 2, b = 8
(3) a = 4, b = 6
(4) a = 6, b = 4
Ans.
Equation of line is
let coordinates of intersection of l with yz plane be [2k+5, (1-b)k+1, (a-1)k+a]
it lies on yz plane,
2k+5 = 0 => k = -5/2
Also (1-b)k+1=17/2 => 1-b = 15/2(-2/5) = -3 => b =4
Also (a-1)k+a =-13/2
A(1+k)-k = -13/2 => a(1-5/2) = -13/2-5/2 = -9
=> -3/2 a = -9 => a = 6
32. If the straight lines
intersect at a point, then the integer k is equal to
(1) -2
(2) –5
(3) 5
(4) 2
Ans.
S = {(x, y) : y = x + 1 and 0 < x < 2}
T = {(x, y) : x – y is an integer}.
Which one of the following is true ?
(1) T is an equivalence relation on R but S is not
(2) Neither S nor T is an equivalence relations on R
(3) Both S and T are equivalence relation on R
(4) S is an equivalence relation on R but T is not
35. Let f : N Y be a function defined as
f(x) =4x + 3 where
Y = {y N : y = 4x + 3 for some x N}. Show that f is invertible and its inverse is
Ans. To find inverse of f, replace y by x and x by y.i.e.
x = 4f -1(x)+3 => f –1(x) = g(x) = x-3/4
Interims of y
g(y) = y-3/4