Page 1
SECTION-A
1. Let f(x) = |2x
2
+5|x|–3|,x ?R. If m and n denote the
number of points where f is not continuous and not
differentiable respectively, then m + n is equal to :
(1) 5 (2) 2
(3) 0 (4) 3
Ans. (4)
Sol. f(x) = |2x
2
+5|x|–3|
Graph of y = |2x
2
+ 5x – 3|
Graph of f(x)
0
Number of points of discontinuity = 0 = m
Number of points of non-differentiability = 3 = n
2. Let ? and ? be the roots of the equation px
2
+ qx –
r = 0, where p ? 0. If p, q and r be the consecutive
terms of a non-constant G.P and , then
the value of ( ??– ??
? ?
is : ?
(1) (2) 9
(3) (4) 8
Ans. (1)
Sol. px
2
+ qx – r = 0
p = A, q = AR, r = AR
2
Ax
2
+ ARx – AR
2
= 0
x
2
+ Rx – R
2
= 0
?? ?
( ? ?? ? ?)
2
= ( ? ??)
2
– 4 ?? ? = R
2
– 4(–R
2
) = 5
= 80/9
3. The number of solutions of the equation 4 sin
2
x – 4
cos
3
x + 9 – 4 cosx = 0; x ? [ –2 ?, 2 ?] is :
(1) 1
(2) 3
(3) 2
(4) 0
Ans. (4)
Sol. 4sin
2
x – 4cos
3
x + 9 – 4 cosx = 0 ; x ? [ – 2 ??, 2 ?]
4 – 4cos
2
x – 4cos
3
x + 9 – 4 cosx = 0
4cos
3
x + 4cos
2
x + 4 cosx – 13 = 0
4cos
3
x + 4cos
2
x + 4cosx = 13
L.H.S. ? 12 can’t be equal to 13.
4. The value of dx is equal to:
(1) 0
(2) 1
(3) 2
(4) –1
Ans. (1)
Sol.
Using where f(2a–x) = –f(x)
Here f(1–x) = f(x)
? I = 0
–3
1/2 – 5 / 4
1 1 3
4
??
??
80
9
20
3
?
?
?
?
1 1 3
4
??
??
2
3 R 4
R
4 R 4 3
? ? ? ? ?
? ? ? ? ?
? ? ?
16
9
??
??
??
1
1 32
3
0
(2x 3x x 1) ? ? ?
?
? ?
1
1
3
32
0
I 2x 3x x 1 dx ? ? ? ?
?
? ?
?
2a
0
f x dx
Page 2
SECTION-A
1. Let f(x) = |2x
2
+5|x|–3|,x ?R. If m and n denote the
number of points where f is not continuous and not
differentiable respectively, then m + n is equal to :
(1) 5 (2) 2
(3) 0 (4) 3
Ans. (4)
Sol. f(x) = |2x
2
+5|x|–3|
Graph of y = |2x
2
+ 5x – 3|
Graph of f(x)
0
Number of points of discontinuity = 0 = m
Number of points of non-differentiability = 3 = n
2. Let ? and ? be the roots of the equation px
2
+ qx –
r = 0, where p ? 0. If p, q and r be the consecutive
terms of a non-constant G.P and , then
the value of ( ??– ??
? ?
is : ?
(1) (2) 9
(3) (4) 8
Ans. (1)
Sol. px
2
+ qx – r = 0
p = A, q = AR, r = AR
2
Ax
2
+ ARx – AR
2
= 0
x
2
+ Rx – R
2
= 0
?? ?
( ? ?? ? ?)
2
= ( ? ??)
2
– 4 ?? ? = R
2
– 4(–R
2
) = 5
= 80/9
3. The number of solutions of the equation 4 sin
2
x – 4
cos
3
x + 9 – 4 cosx = 0; x ? [ –2 ?, 2 ?] is :
(1) 1
(2) 3
(3) 2
(4) 0
Ans. (4)
Sol. 4sin
2
x – 4cos
3
x + 9 – 4 cosx = 0 ; x ? [ – 2 ??, 2 ?]
4 – 4cos
2
x – 4cos
3
x + 9 – 4 cosx = 0
4cos
3
x + 4cos
2
x + 4 cosx – 13 = 0
4cos
3
x + 4cos
2
x + 4cosx = 13
L.H.S. ? 12 can’t be equal to 13.
4. The value of dx is equal to:
(1) 0
(2) 1
(3) 2
(4) –1
Ans. (1)
Sol.
Using where f(2a–x) = –f(x)
Here f(1–x) = f(x)
? I = 0
–3
1/2 – 5 / 4
1 1 3
4
??
??
80
9
20
3
?
?
?
?
1 1 3
4
??
??
2
3 R 4
R
4 R 4 3
? ? ? ? ?
? ? ? ? ?
? ? ?
16
9
??
??
??
1
1 32
3
0
(2x 3x x 1) ? ? ?
?
? ?
1
1
3
32
0
I 2x 3x x 1 dx ? ? ? ?
?
? ?
?
2a
0
f x dx
5. Let P be a point on the ellipse . Let the
line passing through P and parallel to y-axis meet
the circle x
2
+ y
2
= 9 at point Q such that P and Q
are on the same side of the x-axis. Then, the
eccentricity of the locus of the point R on PQ such
that PR : RQ = 4 : 3 as P moves on the ellipse, is :
(1) (2)
(3) (4)
Ans. (4)
Sol.
h = 3cos ?;
? locus =
6. Let m and n be the coefficients of seventh and
thirteenth terms respectively in the expansion of
. Then is :
(1) (2)
(3) (4)
Ans. (4)
Sol.
:
7. Let ? be a non-zero real number. Suppose f : R ?
R is a differentiable function such that f (0) = 2 and
? ?
x
lim f x 1
? ? ?
? . If f '(x) = ?f(x) +3, for all x ? R,
then f (–log
e
2) is equal to____.
(1) 3 (2) 5
(3) 9 (4) 7
Ans. (3 OR BONUS)
Sol. f(0) = 2,
? ?
x
lim f x 1
? ? ?
?
f’(x) – x.f(x) = 3
I.F = e
– ?x
y(e
– ?x
) =
f(x). (e
– ?x
) =
x = 0 ? ? (1)
f(x) =
x ? – ? ?? 1 =
? = –3 ? c = 1
= 1 + e
3ln2
= 9
(But ? should be greater than 0 for finite
value of c)
22
xy
1
94
??
11
19
13
21
139
23
13
7
Q
P(3cos , 2sin ) ? ?
Q(3cos , 3sin ) ? ?
P
2 2
x y
1
9 4
? ?
4
P
(3C, 2S)
R
(h, k)
Q
(3C, 3S)
3
18
k sin
7
??
22
x 49y
1
9 324
??
324 117 13
e1
49 9 21 7
? ? ? ?
?
18
1
3
2
3
11
x
3
2x
??
??
?
??
??
1
3
n
m
??
??
??
4
9
1
9
1
4
9
4
18
12
33
xx
3
?
??
??
?
??
??
??
? ?
12 6
12
33
18 18
7 6 6
12 6
x x 1 1
t c c .
32 2
3
?
? ? ? ?
? ? ? ?
??
? ? ? ?
? ? ? ?
? ? ? ?
? ?
6 12
12
33
18 18 –6
13 12 12
6 12
x x 1 1
t c c . .x
32 2
3
?
? ? ? ?
? ? ? ?
??
? ? ? ?
? ? ? ?
? ? ? ?
18 –12 –6
6
m c .3 .2 ?
18 –12 –6
12
n c .2 .3 ?
1
1
2
–12 –6
3
3
12 6
n 2 .3 3 9
m 2 4 3 .2
??
??
? ? ? ?
? ? ?
??
? ? ? ?
? ? ? ?
??
x
3.e dx
??
?
x
3e
c
??
?
??
3
2c
?
??
?
3
c2 ??
?
x
3
c.e
?
?
?
?
3
c(0)
?
?
?
x
3
f ( ln 2) c.e
?
?
? ? ?
?
Page 3
SECTION-A
1. Let f(x) = |2x
2
+5|x|–3|,x ?R. If m and n denote the
number of points where f is not continuous and not
differentiable respectively, then m + n is equal to :
(1) 5 (2) 2
(3) 0 (4) 3
Ans. (4)
Sol. f(x) = |2x
2
+5|x|–3|
Graph of y = |2x
2
+ 5x – 3|
Graph of f(x)
0
Number of points of discontinuity = 0 = m
Number of points of non-differentiability = 3 = n
2. Let ? and ? be the roots of the equation px
2
+ qx –
r = 0, where p ? 0. If p, q and r be the consecutive
terms of a non-constant G.P and , then
the value of ( ??– ??
? ?
is : ?
(1) (2) 9
(3) (4) 8
Ans. (1)
Sol. px
2
+ qx – r = 0
p = A, q = AR, r = AR
2
Ax
2
+ ARx – AR
2
= 0
x
2
+ Rx – R
2
= 0
?? ?
( ? ?? ? ?)
2
= ( ? ??)
2
– 4 ?? ? = R
2
– 4(–R
2
) = 5
= 80/9
3. The number of solutions of the equation 4 sin
2
x – 4
cos
3
x + 9 – 4 cosx = 0; x ? [ –2 ?, 2 ?] is :
(1) 1
(2) 3
(3) 2
(4) 0
Ans. (4)
Sol. 4sin
2
x – 4cos
3
x + 9 – 4 cosx = 0 ; x ? [ – 2 ??, 2 ?]
4 – 4cos
2
x – 4cos
3
x + 9 – 4 cosx = 0
4cos
3
x + 4cos
2
x + 4 cosx – 13 = 0
4cos
3
x + 4cos
2
x + 4cosx = 13
L.H.S. ? 12 can’t be equal to 13.
4. The value of dx is equal to:
(1) 0
(2) 1
(3) 2
(4) –1
Ans. (1)
Sol.
Using where f(2a–x) = –f(x)
Here f(1–x) = f(x)
? I = 0
–3
1/2 – 5 / 4
1 1 3
4
??
??
80
9
20
3
?
?
?
?
1 1 3
4
??
??
2
3 R 4
R
4 R 4 3
? ? ? ? ?
? ? ? ? ?
? ? ?
16
9
??
??
??
1
1 32
3
0
(2x 3x x 1) ? ? ?
?
? ?
1
1
3
32
0
I 2x 3x x 1 dx ? ? ? ?
?
? ?
?
2a
0
f x dx
5. Let P be a point on the ellipse . Let the
line passing through P and parallel to y-axis meet
the circle x
2
+ y
2
= 9 at point Q such that P and Q
are on the same side of the x-axis. Then, the
eccentricity of the locus of the point R on PQ such
that PR : RQ = 4 : 3 as P moves on the ellipse, is :
(1) (2)
(3) (4)
Ans. (4)
Sol.
h = 3cos ?;
? locus =
6. Let m and n be the coefficients of seventh and
thirteenth terms respectively in the expansion of
. Then is :
(1) (2)
(3) (4)
Ans. (4)
Sol.
:
7. Let ? be a non-zero real number. Suppose f : R ?
R is a differentiable function such that f (0) = 2 and
? ?
x
lim f x 1
? ? ?
? . If f '(x) = ?f(x) +3, for all x ? R,
then f (–log
e
2) is equal to____.
(1) 3 (2) 5
(3) 9 (4) 7
Ans. (3 OR BONUS)
Sol. f(0) = 2,
? ?
x
lim f x 1
? ? ?
?
f’(x) – x.f(x) = 3
I.F = e
– ?x
y(e
– ?x
) =
f(x). (e
– ?x
) =
x = 0 ? ? (1)
f(x) =
x ? – ? ?? 1 =
? = –3 ? c = 1
= 1 + e
3ln2
= 9
(But ? should be greater than 0 for finite
value of c)
22
xy
1
94
??
11
19
13
21
139
23
13
7
Q
P(3cos , 2sin ) ? ?
Q(3cos , 3sin ) ? ?
P
2 2
x y
1
9 4
? ?
4
P
(3C, 2S)
R
(h, k)
Q
(3C, 3S)
3
18
k sin
7
??
22
x 49y
1
9 324
??
324 117 13
e1
49 9 21 7
? ? ? ?
?
18
1
3
2
3
11
x
3
2x
??
??
?
??
??
1
3
n
m
??
??
??
4
9
1
9
1
4
9
4
18
12
33
xx
3
?
??
??
?
??
??
??
? ?
12 6
12
33
18 18
7 6 6
12 6
x x 1 1
t c c .
32 2
3
?
? ? ? ?
? ? ? ?
??
? ? ? ?
? ? ? ?
? ? ? ?
? ?
6 12
12
33
18 18 –6
13 12 12
6 12
x x 1 1
t c c . .x
32 2
3
?
? ? ? ?
? ? ? ?
??
? ? ? ?
? ? ? ?
? ? ? ?
18 –12 –6
6
m c .3 .2 ?
18 –12 –6
12
n c .2 .3 ?
1
1
2
–12 –6
3
3
12 6
n 2 .3 3 9
m 2 4 3 .2
??
??
? ? ? ?
? ? ?
??
? ? ? ?
? ? ? ?
??
x
3.e dx
??
?
x
3e
c
??
?
??
3
2c
?
??
?
3
c2 ??
?
x
3
c.e
?
?
?
?
3
c(0)
?
?
?
x
3
f ( ln 2) c.e
?
?
? ? ?
?
8. Let P and Q be the points on the line
which are at a distance of 6
units from the point R (1,2,3). If the centroid of the
triangle PQR is ( ?, ? ?, ?), then ?
2
+ ? ?
2
+ ??
2
is:
(1) 26
(2) 36
(3) 18
(4) 24
Ans. (3)
Sol.
P(8 ?? – 3, 2 ? + 4, 2 ? – 1)
PR = 6
(8 ?? – 4)
2
+ ( 2 ? + 2)
2
+ (2 ? – 4)
2
= 36
? = 0, 1
Hence P(–3, 4, –1) & Q(5, 6, 1)
Centroid of ?PQR = (1, 4, 1) ? ( ?, ? ?, ?)
?
??
+ ?
?
+ ?
?
= 18
9. Consider a ?ABC where A(1,2,3,), B(–2,8,0) and
C(3,6,7). If the angle bisector of ?BAC meets the
line BC at D, then the length of the projection of
the vector on the vector is:
(1)
(2)
(3)
(4)
Ans. (1)
Sol.
A(1, 3, 2); B(–2, 8, 0); C(3, 6, 7);
AB =
AC =
Length of projection of on
=
10. Let S
n
denote the sum of the first n terms of an
arithmetic progression. If S
10
= 390 and the ratio of
the tenth and the fifth terms is 15 : 7, then S
15
–S
5
is equal to:
(1) 800
(2) 890
(3) 790
(4) 690
Ans. (3)
Sol. S
10
= 390
? 2a + 9d = 78 (1)
(2)
From (1) & (2) a = 3 & d = 8
=790
x 3 y 4 z 1
8 2 2
? ? ?
??
P Q
R(1,2,3)
AD
?
AC
?
37
2 38
38
2
39
2 38
19
A (1,3,2)
C (3, 6, 7) B
(–2, 8, 0)
D
1 : 1
1 7
, 7,
2 2
? ?
? ?
? ?
ˆ ˆ ˆ
AC 2i 3j 5k ? ? ?
9 25 4 38 ? ? ?
4 9 25 38 ? ? ?
1 3 1
ˆ ˆ ˆ ˆ ˆ ˆ
AD i 4j k (i 8j 3k)
2 2 2
? ? ? ? ? ?
AD AC
AD.AC 37
| AC | 2 38
?
? ?
10
2a 10 1 d 390
2
?? ? ? ?
??
10
5
t 15 a 9d 15
8a 3d
t 7 a 4d 7
?
? ? ? ? ?
?
? ? ? ?
15 5
15 5
S – S 6 14 8 6 4 8
22
? ? ? ? ? ?
15 118 5 38
2
? ? ?
?
Page 4
SECTION-A
1. Let f(x) = |2x
2
+5|x|–3|,x ?R. If m and n denote the
number of points where f is not continuous and not
differentiable respectively, then m + n is equal to :
(1) 5 (2) 2
(3) 0 (4) 3
Ans. (4)
Sol. f(x) = |2x
2
+5|x|–3|
Graph of y = |2x
2
+ 5x – 3|
Graph of f(x)
0
Number of points of discontinuity = 0 = m
Number of points of non-differentiability = 3 = n
2. Let ? and ? be the roots of the equation px
2
+ qx –
r = 0, where p ? 0. If p, q and r be the consecutive
terms of a non-constant G.P and , then
the value of ( ??– ??
? ?
is : ?
(1) (2) 9
(3) (4) 8
Ans. (1)
Sol. px
2
+ qx – r = 0
p = A, q = AR, r = AR
2
Ax
2
+ ARx – AR
2
= 0
x
2
+ Rx – R
2
= 0
?? ?
( ? ?? ? ?)
2
= ( ? ??)
2
– 4 ?? ? = R
2
– 4(–R
2
) = 5
= 80/9
3. The number of solutions of the equation 4 sin
2
x – 4
cos
3
x + 9 – 4 cosx = 0; x ? [ –2 ?, 2 ?] is :
(1) 1
(2) 3
(3) 2
(4) 0
Ans. (4)
Sol. 4sin
2
x – 4cos
3
x + 9 – 4 cosx = 0 ; x ? [ – 2 ??, 2 ?]
4 – 4cos
2
x – 4cos
3
x + 9 – 4 cosx = 0
4cos
3
x + 4cos
2
x + 4 cosx – 13 = 0
4cos
3
x + 4cos
2
x + 4cosx = 13
L.H.S. ? 12 can’t be equal to 13.
4. The value of dx is equal to:
(1) 0
(2) 1
(3) 2
(4) –1
Ans. (1)
Sol.
Using where f(2a–x) = –f(x)
Here f(1–x) = f(x)
? I = 0
–3
1/2 – 5 / 4
1 1 3
4
??
??
80
9
20
3
?
?
?
?
1 1 3
4
??
??
2
3 R 4
R
4 R 4 3
? ? ? ? ?
? ? ? ? ?
? ? ?
16
9
??
??
??
1
1 32
3
0
(2x 3x x 1) ? ? ?
?
? ?
1
1
3
32
0
I 2x 3x x 1 dx ? ? ? ?
?
? ?
?
2a
0
f x dx
5. Let P be a point on the ellipse . Let the
line passing through P and parallel to y-axis meet
the circle x
2
+ y
2
= 9 at point Q such that P and Q
are on the same side of the x-axis. Then, the
eccentricity of the locus of the point R on PQ such
that PR : RQ = 4 : 3 as P moves on the ellipse, is :
(1) (2)
(3) (4)
Ans. (4)
Sol.
h = 3cos ?;
? locus =
6. Let m and n be the coefficients of seventh and
thirteenth terms respectively in the expansion of
. Then is :
(1) (2)
(3) (4)
Ans. (4)
Sol.
:
7. Let ? be a non-zero real number. Suppose f : R ?
R is a differentiable function such that f (0) = 2 and
? ?
x
lim f x 1
? ? ?
? . If f '(x) = ?f(x) +3, for all x ? R,
then f (–log
e
2) is equal to____.
(1) 3 (2) 5
(3) 9 (4) 7
Ans. (3 OR BONUS)
Sol. f(0) = 2,
? ?
x
lim f x 1
? ? ?
?
f’(x) – x.f(x) = 3
I.F = e
– ?x
y(e
– ?x
) =
f(x). (e
– ?x
) =
x = 0 ? ? (1)
f(x) =
x ? – ? ?? 1 =
? = –3 ? c = 1
= 1 + e
3ln2
= 9
(But ? should be greater than 0 for finite
value of c)
22
xy
1
94
??
11
19
13
21
139
23
13
7
Q
P(3cos , 2sin ) ? ?
Q(3cos , 3sin ) ? ?
P
2 2
x y
1
9 4
? ?
4
P
(3C, 2S)
R
(h, k)
Q
(3C, 3S)
3
18
k sin
7
??
22
x 49y
1
9 324
??
324 117 13
e1
49 9 21 7
? ? ? ?
?
18
1
3
2
3
11
x
3
2x
??
??
?
??
??
1
3
n
m
??
??
??
4
9
1
9
1
4
9
4
18
12
33
xx
3
?
??
??
?
??
??
??
? ?
12 6
12
33
18 18
7 6 6
12 6
x x 1 1
t c c .
32 2
3
?
? ? ? ?
? ? ? ?
??
? ? ? ?
? ? ? ?
? ? ? ?
? ?
6 12
12
33
18 18 –6
13 12 12
6 12
x x 1 1
t c c . .x
32 2
3
?
? ? ? ?
? ? ? ?
??
? ? ? ?
? ? ? ?
? ? ? ?
18 –12 –6
6
m c .3 .2 ?
18 –12 –6
12
n c .2 .3 ?
1
1
2
–12 –6
3
3
12 6
n 2 .3 3 9
m 2 4 3 .2
??
??
? ? ? ?
? ? ?
??
? ? ? ?
? ? ? ?
??
x
3.e dx
??
?
x
3e
c
??
?
??
3
2c
?
??
?
3
c2 ??
?
x
3
c.e
?
?
?
?
3
c(0)
?
?
?
x
3
f ( ln 2) c.e
?
?
? ? ?
?
8. Let P and Q be the points on the line
which are at a distance of 6
units from the point R (1,2,3). If the centroid of the
triangle PQR is ( ?, ? ?, ?), then ?
2
+ ? ?
2
+ ??
2
is:
(1) 26
(2) 36
(3) 18
(4) 24
Ans. (3)
Sol.
P(8 ?? – 3, 2 ? + 4, 2 ? – 1)
PR = 6
(8 ?? – 4)
2
+ ( 2 ? + 2)
2
+ (2 ? – 4)
2
= 36
? = 0, 1
Hence P(–3, 4, –1) & Q(5, 6, 1)
Centroid of ?PQR = (1, 4, 1) ? ( ?, ? ?, ?)
?
??
+ ?
?
+ ?
?
= 18
9. Consider a ?ABC where A(1,2,3,), B(–2,8,0) and
C(3,6,7). If the angle bisector of ?BAC meets the
line BC at D, then the length of the projection of
the vector on the vector is:
(1)
(2)
(3)
(4)
Ans. (1)
Sol.
A(1, 3, 2); B(–2, 8, 0); C(3, 6, 7);
AB =
AC =
Length of projection of on
=
10. Let S
n
denote the sum of the first n terms of an
arithmetic progression. If S
10
= 390 and the ratio of
the tenth and the fifth terms is 15 : 7, then S
15
–S
5
is equal to:
(1) 800
(2) 890
(3) 790
(4) 690
Ans. (3)
Sol. S
10
= 390
? 2a + 9d = 78 (1)
(2)
From (1) & (2) a = 3 & d = 8
=790
x 3 y 4 z 1
8 2 2
? ? ?
??
P Q
R(1,2,3)
AD
?
AC
?
37
2 38
38
2
39
2 38
19
A (1,3,2)
C (3, 6, 7) B
(–2, 8, 0)
D
1 : 1
1 7
, 7,
2 2
? ?
? ?
? ?
ˆ ˆ ˆ
AC 2i 3j 5k ? ? ?
9 25 4 38 ? ? ?
4 9 25 38 ? ? ?
1 3 1
ˆ ˆ ˆ ˆ ˆ ˆ
AD i 4j k (i 8j 3k)
2 2 2
? ? ? ? ? ?
AD AC
AD.AC 37
| AC | 2 38
?
? ?
10
2a 10 1 d 390
2
?? ? ? ?
??
10
5
t 15 a 9d 15
8a 3d
t 7 a 4d 7
?
? ? ? ? ?
?
? ? ? ?
15 5
15 5
S – S 6 14 8 6 4 8
22
? ? ? ? ? ?
15 118 5 38
2
? ? ?
?
11. If , where a and b are
rational numbers, then 9a + 8b is equal to :
(1) 2 (2) 1
(3) 3 (4)
Ans. (1)
Sol.
=
?
? 9a + 8b =
12. If z is a complex number such that |z| ?1, then the
minimum value of is:
(1) (2) 2
(3) 3 (4)
Ans. (Bonus)
Sol. |z| ? 1
Min. value of is actually zero.
13. If the domain of the function f(x) =
+log
10
(x
2
+ 2x – 15) is (– ?, ?) U [ ?, ?), then
?
2
+ ?
3
is equal to :
(1) 140 (2) 175
(3) 150 (4) 125
Ans. (3)
Sol. ƒ(x) = + log
10
(x
2
+ 2x - 15)
Domain : x
2
– 25 ? 0 ? x ? (– ?, -5] ? [5, ?)
4 – x
2
? 0 ? x ?{–2, 2}
x
2
+ 2x – 15 > 0 ? (x + 5) (x – 3) > 0
? x ? (– ?, –5) ? (3, ?)
??x ? (– ?, –5) ? [5, ??)
??= –5; ??= 5
? ??
?
?? ? ?
3
?= 150
14. Consider the relations R
1
and R
2
defined as aR
1
b
? a
2
+ b
2
= 1 for all a , b, ? R and (a, b) R
2
(c, d)
? a + d = b + c for all (a,b), (c,d) ? N × N. Then
(1) Only R
1
is an equivalence relation
(2) Only R
2
is an equivalence relation
(3) R
1
and R
2
both are equivalence relations
(4) Neither R
1
nor R
2
is an equivalence relation
Ans. (2)
Sol. aR
1
b ? a
2
+ b
2
= 1; a, b ? R
(a, b) R
2
(c, d) ? a + d = b + c; (a, b), (c, d) ? N
for R
1
: Not reflexive symmetric not transitive
for R
2
: R
2
is reflexive, symmetric and transitive
Hence only R
2
is equivalence relation.
3
4
0
cos x dx a b 3
?
? ? ?
?
3
2
/3
4
0
cos xdx
?
?
2
/3
0
1 cos2x
dx
2
?
???
?
??
??
?
/3
2
0
1
(1 2cos2x cos 2x)dx
4
?
? ? ?
?
/3 /3 /3
0 0 0
1 1 cos4x
dx 2 cos2x dx dx
42
? ? ?
??
?
? ? ?
??
??
? ? ?
/3 /3
00
1 1 1
(sin 2x) (sin 4x)
4 3 2 3 8
??
?? ?? ??
? ? ? ?
?? ??
?? ??
/3 /3
00
1 1 1
(sin 2x) (sin 4x)
4 3 2 3 8
??
?? ?? ??
? ? ? ?
?? ??
?? ??
1 3 1 3
4 2 2 8 2
?? ??
?
? ? ? ? ?
?? ??
??
??
?? ??
73
2 64
?
?
17
a ; b
8 64
??
97
2
88
??
1
z (3 4
2
?? i)
5
2
3
2
O
P
3
, 2
2
? ? ?
?
? ?
? ?
3
z 2i
2
??
2
2
x 25
(4 x )
?
?
2
2
x 25
4x
?
?
Page 5
SECTION-A
1. Let f(x) = |2x
2
+5|x|–3|,x ?R. If m and n denote the
number of points where f is not continuous and not
differentiable respectively, then m + n is equal to :
(1) 5 (2) 2
(3) 0 (4) 3
Ans. (4)
Sol. f(x) = |2x
2
+5|x|–3|
Graph of y = |2x
2
+ 5x – 3|
Graph of f(x)
0
Number of points of discontinuity = 0 = m
Number of points of non-differentiability = 3 = n
2. Let ? and ? be the roots of the equation px
2
+ qx –
r = 0, where p ? 0. If p, q and r be the consecutive
terms of a non-constant G.P and , then
the value of ( ??– ??
? ?
is : ?
(1) (2) 9
(3) (4) 8
Ans. (1)
Sol. px
2
+ qx – r = 0
p = A, q = AR, r = AR
2
Ax
2
+ ARx – AR
2
= 0
x
2
+ Rx – R
2
= 0
?? ?
( ? ?? ? ?)
2
= ( ? ??)
2
– 4 ?? ? = R
2
– 4(–R
2
) = 5
= 80/9
3. The number of solutions of the equation 4 sin
2
x – 4
cos
3
x + 9 – 4 cosx = 0; x ? [ –2 ?, 2 ?] is :
(1) 1
(2) 3
(3) 2
(4) 0
Ans. (4)
Sol. 4sin
2
x – 4cos
3
x + 9 – 4 cosx = 0 ; x ? [ – 2 ??, 2 ?]
4 – 4cos
2
x – 4cos
3
x + 9 – 4 cosx = 0
4cos
3
x + 4cos
2
x + 4 cosx – 13 = 0
4cos
3
x + 4cos
2
x + 4cosx = 13
L.H.S. ? 12 can’t be equal to 13.
4. The value of dx is equal to:
(1) 0
(2) 1
(3) 2
(4) –1
Ans. (1)
Sol.
Using where f(2a–x) = –f(x)
Here f(1–x) = f(x)
? I = 0
–3
1/2 – 5 / 4
1 1 3
4
??
??
80
9
20
3
?
?
?
?
1 1 3
4
??
??
2
3 R 4
R
4 R 4 3
? ? ? ? ?
? ? ? ? ?
? ? ?
16
9
??
??
??
1
1 32
3
0
(2x 3x x 1) ? ? ?
?
? ?
1
1
3
32
0
I 2x 3x x 1 dx ? ? ? ?
?
? ?
?
2a
0
f x dx
5. Let P be a point on the ellipse . Let the
line passing through P and parallel to y-axis meet
the circle x
2
+ y
2
= 9 at point Q such that P and Q
are on the same side of the x-axis. Then, the
eccentricity of the locus of the point R on PQ such
that PR : RQ = 4 : 3 as P moves on the ellipse, is :
(1) (2)
(3) (4)
Ans. (4)
Sol.
h = 3cos ?;
? locus =
6. Let m and n be the coefficients of seventh and
thirteenth terms respectively in the expansion of
. Then is :
(1) (2)
(3) (4)
Ans. (4)
Sol.
:
7. Let ? be a non-zero real number. Suppose f : R ?
R is a differentiable function such that f (0) = 2 and
? ?
x
lim f x 1
? ? ?
? . If f '(x) = ?f(x) +3, for all x ? R,
then f (–log
e
2) is equal to____.
(1) 3 (2) 5
(3) 9 (4) 7
Ans. (3 OR BONUS)
Sol. f(0) = 2,
? ?
x
lim f x 1
? ? ?
?
f’(x) – x.f(x) = 3
I.F = e
– ?x
y(e
– ?x
) =
f(x). (e
– ?x
) =
x = 0 ? ? (1)
f(x) =
x ? – ? ?? 1 =
? = –3 ? c = 1
= 1 + e
3ln2
= 9
(But ? should be greater than 0 for finite
value of c)
22
xy
1
94
??
11
19
13
21
139
23
13
7
Q
P(3cos , 2sin ) ? ?
Q(3cos , 3sin ) ? ?
P
2 2
x y
1
9 4
? ?
4
P
(3C, 2S)
R
(h, k)
Q
(3C, 3S)
3
18
k sin
7
??
22
x 49y
1
9 324
??
324 117 13
e1
49 9 21 7
? ? ? ?
?
18
1
3
2
3
11
x
3
2x
??
??
?
??
??
1
3
n
m
??
??
??
4
9
1
9
1
4
9
4
18
12
33
xx
3
?
??
??
?
??
??
??
? ?
12 6
12
33
18 18
7 6 6
12 6
x x 1 1
t c c .
32 2
3
?
? ? ? ?
? ? ? ?
??
? ? ? ?
? ? ? ?
? ? ? ?
? ?
6 12
12
33
18 18 –6
13 12 12
6 12
x x 1 1
t c c . .x
32 2
3
?
? ? ? ?
? ? ? ?
??
? ? ? ?
? ? ? ?
? ? ? ?
18 –12 –6
6
m c .3 .2 ?
18 –12 –6
12
n c .2 .3 ?
1
1
2
–12 –6
3
3
12 6
n 2 .3 3 9
m 2 4 3 .2
??
??
? ? ? ?
? ? ?
??
? ? ? ?
? ? ? ?
??
x
3.e dx
??
?
x
3e
c
??
?
??
3
2c
?
??
?
3
c2 ??
?
x
3
c.e
?
?
?
?
3
c(0)
?
?
?
x
3
f ( ln 2) c.e
?
?
? ? ?
?
8. Let P and Q be the points on the line
which are at a distance of 6
units from the point R (1,2,3). If the centroid of the
triangle PQR is ( ?, ? ?, ?), then ?
2
+ ? ?
2
+ ??
2
is:
(1) 26
(2) 36
(3) 18
(4) 24
Ans. (3)
Sol.
P(8 ?? – 3, 2 ? + 4, 2 ? – 1)
PR = 6
(8 ?? – 4)
2
+ ( 2 ? + 2)
2
+ (2 ? – 4)
2
= 36
? = 0, 1
Hence P(–3, 4, –1) & Q(5, 6, 1)
Centroid of ?PQR = (1, 4, 1) ? ( ?, ? ?, ?)
?
??
+ ?
?
+ ?
?
= 18
9. Consider a ?ABC where A(1,2,3,), B(–2,8,0) and
C(3,6,7). If the angle bisector of ?BAC meets the
line BC at D, then the length of the projection of
the vector on the vector is:
(1)
(2)
(3)
(4)
Ans. (1)
Sol.
A(1, 3, 2); B(–2, 8, 0); C(3, 6, 7);
AB =
AC =
Length of projection of on
=
10. Let S
n
denote the sum of the first n terms of an
arithmetic progression. If S
10
= 390 and the ratio of
the tenth and the fifth terms is 15 : 7, then S
15
–S
5
is equal to:
(1) 800
(2) 890
(3) 790
(4) 690
Ans. (3)
Sol. S
10
= 390
? 2a + 9d = 78 (1)
(2)
From (1) & (2) a = 3 & d = 8
=790
x 3 y 4 z 1
8 2 2
? ? ?
??
P Q
R(1,2,3)
AD
?
AC
?
37
2 38
38
2
39
2 38
19
A (1,3,2)
C (3, 6, 7) B
(–2, 8, 0)
D
1 : 1
1 7
, 7,
2 2
? ?
? ?
? ?
ˆ ˆ ˆ
AC 2i 3j 5k ? ? ?
9 25 4 38 ? ? ?
4 9 25 38 ? ? ?
1 3 1
ˆ ˆ ˆ ˆ ˆ ˆ
AD i 4j k (i 8j 3k)
2 2 2
? ? ? ? ? ?
AD AC
AD.AC 37
| AC | 2 38
?
? ?
10
2a 10 1 d 390
2
?? ? ? ?
??
10
5
t 15 a 9d 15
8a 3d
t 7 a 4d 7
?
? ? ? ? ?
?
? ? ? ?
15 5
15 5
S – S 6 14 8 6 4 8
22
? ? ? ? ? ?
15 118 5 38
2
? ? ?
?
11. If , where a and b are
rational numbers, then 9a + 8b is equal to :
(1) 2 (2) 1
(3) 3 (4)
Ans. (1)
Sol.
=
?
? 9a + 8b =
12. If z is a complex number such that |z| ?1, then the
minimum value of is:
(1) (2) 2
(3) 3 (4)
Ans. (Bonus)
Sol. |z| ? 1
Min. value of is actually zero.
13. If the domain of the function f(x) =
+log
10
(x
2
+ 2x – 15) is (– ?, ?) U [ ?, ?), then
?
2
+ ?
3
is equal to :
(1) 140 (2) 175
(3) 150 (4) 125
Ans. (3)
Sol. ƒ(x) = + log
10
(x
2
+ 2x - 15)
Domain : x
2
– 25 ? 0 ? x ? (– ?, -5] ? [5, ?)
4 – x
2
? 0 ? x ?{–2, 2}
x
2
+ 2x – 15 > 0 ? (x + 5) (x – 3) > 0
? x ? (– ?, –5) ? (3, ?)
??x ? (– ?, –5) ? [5, ??)
??= –5; ??= 5
? ??
?
?? ? ?
3
?= 150
14. Consider the relations R
1
and R
2
defined as aR
1
b
? a
2
+ b
2
= 1 for all a , b, ? R and (a, b) R
2
(c, d)
? a + d = b + c for all (a,b), (c,d) ? N × N. Then
(1) Only R
1
is an equivalence relation
(2) Only R
2
is an equivalence relation
(3) R
1
and R
2
both are equivalence relations
(4) Neither R
1
nor R
2
is an equivalence relation
Ans. (2)
Sol. aR
1
b ? a
2
+ b
2
= 1; a, b ? R
(a, b) R
2
(c, d) ? a + d = b + c; (a, b), (c, d) ? N
for R
1
: Not reflexive symmetric not transitive
for R
2
: R
2
is reflexive, symmetric and transitive
Hence only R
2
is equivalence relation.
3
4
0
cos x dx a b 3
?
? ? ?
?
3
2
/3
4
0
cos xdx
?
?
2
/3
0
1 cos2x
dx
2
?
???
?
??
??
?
/3
2
0
1
(1 2cos2x cos 2x)dx
4
?
? ? ?
?
/3 /3 /3
0 0 0
1 1 cos4x
dx 2 cos2x dx dx
42
? ? ?
??
?
? ? ?
??
??
? ? ?
/3 /3
00
1 1 1
(sin 2x) (sin 4x)
4 3 2 3 8
??
?? ?? ??
? ? ? ?
?? ??
?? ??
/3 /3
00
1 1 1
(sin 2x) (sin 4x)
4 3 2 3 8
??
?? ?? ??
? ? ? ?
?? ??
?? ??
1 3 1 3
4 2 2 8 2
?? ??
?
? ? ? ? ?
?? ??
??
??
?? ??
73
2 64
?
?
17
a ; b
8 64
??
97
2
88
??
1
z (3 4
2
?? i)
5
2
3
2
O
P
3
, 2
2
? ? ?
?
? ?
? ?
3
z 2i
2
??
2
2
x 25
(4 x )
?
?
2
2
x 25
4x
?
?
15. If the mirror image of the point P(3,4,9) in the line
is ( ?, ? ?, ?), then 14 ( ??+ ? ? + ?)
is :
(1) 102 (2) 138
(3) 108 (4) 132
Ans. (3)
Sol.
?
3(3?? – 2) + 2 (2 ?? – 5) + ( ? – 7) = 0
14 ?? = 23 ? ?? ? ? ? ?
? ?
? ?? ?
? ?
? ?
Ans. 14 ( ? ?? ? ? ? ? ?r) = 108
16. Let f(x) = x ? N. If for some
a ? ?N, f(f(f(a))) = 21, then
where [t] denotes the greatest integer less than or
equal to t, is equal to :
(1) 121
(2) 144
(3) 169
(4) 225
Ans. (2)
Sol. ƒ(x) =
ƒ(ƒ(ƒ(a))) = 21
C –1: If a = even
ƒ(a) = a – 1 = odd
f(f(a)) = 2(a – 1) = even
ƒ(ƒ(ƒ(a))) = 2a – 3 = 21 ? a = 12
C –2: If a = odd
ƒ(a) = 2a = even
ƒ(ƒ(a)) = 2a – 1 = odd
ƒ(ƒ(ƒ(a))) = 4a – 2 = 21 (Not possible)
Hence a = 12
Now
= 144 – 0 = 144.
17. Let the system of equations x + 2y +3z = 5, 2x +
3y + z = 9, 4x + 3y + ?z = ? have infinite number
of solutions. Then ? + 2??is equal to :
(1) 28 (2) 17
(3) 22 (4) 15
Ans. (2)
Sol. x + 2y + 3z = 5
2x + 3y + z = 9
4x + 3y + ?z = µ
for infinite following ? = ?
1
= ?
2
= ?
3
= 0
? ?? ?= 0 ?? ? ?? –13
?
?
?? ? = 0 ??? = 15
?
?
?? ?= 0
x 1 y 1 z 2
3 2 1
? ? ?
??
P(3, 4, 9)
A( , ) ? ?? ?
N
(3 + 1, 2 –1, + 2) ? ? ?
PN.b 0 ?
23
14
83 32 51
N , ,
14 14 14
??
??
??
3 83 62
2 14 7
??
? ? ? ?
4 32 4
2 14 7
??
? ? ? ?
9 51 12
2 14 7
? ? ?
? ? ? ?
x 1,xis even,
2x, xis odd,
? ?
?
?
xa
lim
?
?
3
| x | x
,
aa
??
??
?
??
??
??
??
x 1; x even
2x; x odd
?? ?
?
?
?
3
x 12
| x | x
lim
2 12
?
?
??
??
?
??
??
??
??
3
x 12 x 12
| x | x
lim lim
12 12
??
??
??
??
??
??
1 2 3
2 3 1
43 ?
5 2 3
9 3 1
µ 3 13 ?
1 5 3
2 9 1
4 15 13 ?
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