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AIEEE Home page 2008 AIEEE PAPER - (Math)

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Mean of the numbers: (a+b+8+5+10)/5=6
a+b=7 ......... (i)
variance = 6.8 = {(a-6)2+(b-6)2+(8-6)2+(5-6)2+(10-6)2}
a2+b2+93-12(a+b)=34 ........... (ii)
By solving (i) and (ii)
a=3 , b=4

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a, b and c are coplanar, so
a.(b x c) = 0
So, (αi + 2j + βk).(i - j + k) = 0
=> α + β = 2
a bisect the angle between b and c
So a = (λ/) (b + c)
=> a = (λ/) (i+2j+k)
=> (αi + 2j + βk) = (λ/) (i+2j+k)
=> So, λ =
=> So, α=1 , β=1

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The vector and are parallel and are in opposite direction.
So angle between them is 180° = π

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Let A = (5, 1, a)
Let B = (3, b, 1)
Let C = ( 0 , 17/2 , -13/2 )
Point A , B and C are in straight line
So,
5 1 a
3 b 1
0 17/2 -13/2
= 0

=> 51a - 65b = 46
So, a = 6, b = 4

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As the two given lines are intersecting, so
2-1 3-2 1-3
k 2 3
3 k 2
= 0

So
1 1 -2
k 2 3
3 k 2
= 0

=> 1(4-3k)-1(2k-9)-2(k2-6)=0
=> 2k2 + 5k - 25 = 0
=> k=-5 OR k=5/2

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The conjugate of a complex number is given by changing the sign of the imaginary part.
For example: conjugate of a complex number a+ib is a-ib
z = 1/(i-1) = (i+1)/((i-1)(i+1)) = (i+1)/(-2) = -1/2-i/2
So conjugate complex number = -1/2+i/2 = (i-1)/2
So conjugate complex number = ((i-1)(i+1))/(2(i+1)) = -2/2((i+1)) = -1/(i+1)

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In equivalence relation a set satisfies following three conditions:
a. Every member of the set is related to itself.
b. Whenever a is related to b then b is also related to a.
c. If a is related to b and b is related to c, then a is related to c.

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y = 4x + 3
=> x = (y-3)/4
=> f(y) = (y-3)/4

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p : x is an irrational number
q : y is a transcendental number
r : x is a rational number iff y is a transcendental number
=> r : ~ p ↔ q
s1 : q or p
s2 : ~ (p↔~q)
p q ~p ~q r:~p↔q s1:q or p p↔~q s2:~(p↔~q)
T T F F F T F T
T F F T T T T F
F T T F T T T F
FFTTFFFT

Based upon above chart
s1 and r are not equivalent
s2 and r are not equivalent

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x - cy - bz = 0
cx - y - az = 0
bx + ay - z = 0
So,
1 -c -b
c -1 -a
b a -1
= 0

(1 + a2) + c(-c - ab) - b(ca + b) = 0
a2 + b2 + c2 + 2abc = 0

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As det A = ±1
So inverse of matrix A exists
As all entries of matrix A are integers and Adjoint A is matrix of transpose of co-factors of matrix A.
So, Entries of Adjoint A is also integers.

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Let α and β are roots of: x2 - 6x + a = 0
Let α and γ are roots of: x2 - cx + 6 = 0
So, α + β = 6 ........ (i)
α.β = a ........ (ii)

α + γ = c ........ (iii)
α.γ = 6 ........ (iv)

β/γ = 4/3 ........ (v)

Now using (ii) and (iii)
α.β/α.γ = a/6
=> β/γ = a/6
=> using (v), 4/3 = a/6
=> So, a = 8

Now , x2 - 6x + a = 0
x2 - 6x + 8 = 0
x = 2 OR 6
As α.β = 8
So α = 2

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Count of M = 1
Count of I = 4
Count of S = 4
Count of P = 2
Number of ways MISSISSIPPI can be jumbled without using S = (7!)/(4! x 2!)
Now number od ways four S can be placed in MIIIPPI = 8C4
So total number of ways = (7!)/(4! x 2!) x 8C4
So total number of ways = 7 . 6C4 x 8C4

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sinx   < 1 when x ∈ (0, 1) => So, sin   <
x





So,

cosx   <   1   when x ∈ (0, 1)





So,

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x + 2y2 = 0 .............(i)
x + 3y2 = 1 .............(ii)
By solving (i) and (ii)
x = -2 and y = ±1

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p q p V q q→q p→(q→q) p→(p V q)
F F F T T T
F T T F T T
T F T T T T
T T T T T T

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cot(cosec-15/3 + tan-12/3) = cot(tan-13/4 + tan-12/3)
= cot(tan-1(3/4 + 2/3)/(1-(3/4)x(2/3))) = cot(tan-117/6) = 6/17

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A = {4, 5, 6}
B = {1, 2, 3, 4}
A ∪ B = {1, 2, 3, 4, 5, 6}
P(A ∪ B) = 1

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Let the equation of perpendicular bisector is y = mx + c
c = -4
So, y = mx - 4 .............(i)
Center point between P(1, 4) and Q(k, 3) will be ((1+k)/2, 7/2)
In equation (i) passes thru ((1+k)/2, 7/2)
So, 7/2 = m((1+k)/2) - 4
7 = m + mk - 8
m + mk - 15 = 0 .................(ii)
m = gradient of the perpendiculat line
m = - (gradient of PQ) = -(1-k)/(4-3) = k - 1
Replace value of m in equation (ii)
k - 1 + k(k - 1) - 15 = 0
k2 = 16
k = ±4

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a + ar = 12
a(1 + r) = 12
ar2 + ar3 = 48
ar2 (1 + r) = 48
r2 = 4
r = ±2
=> r = -2
=> a = -12

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f(x) = x3 - px + q
So, f'(x) = 3x2 - p = 0
=> x = ±
=> f"(x) = 6x
=> f"(x) at x = is positive
=> So minima is at x =

=> f"(x) at x = is negative
=> So maxima is at x =

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