Page 1
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Tuesday 30
th
January, 2024) TIME : 9 : 00 AM to 12 : 00 NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. A line passing through the point A(9, 0) makes an angle
of 30º with the positive direction of x-axis. If this line is
rotated about A through an angle of 15º in the clockwise
direction, then its equation in the new position is
(1) 9
3 2
?K?]
?M y
x (2) 9
3 2
?K?]
?M x
y
(3) 9
3 2
?K?]
?K x
y (4) 9
3 2
?K?]
?K y
x
Ans. (1)
Sol.
Eq
n
: y – 0 = tan15° (x – 9) ?? y = (2 ?M 3 ?I?@ (x ?M 9)
2. Let S
a
denote the sum of first n terms an arithmetic
progression. If S
20
= 790 and S
10
= 145, then S
15
–
S
5
is :
(1) 395
(2) 390
(3) 405
(4) 410
Ans. (1)
Sol.
?{ ?} 20
20
S 2a 19d 790
2
?] ?K ?]
2a + 19d = 79 …..(1)
?{ ?} 10
10
S 2a 9d 145
2
?] ?K ?]
2a + 9d = 29 …..(2)
From (1) and (2) a = -8, d = 5
?{ ?} ?{ ?} 15 5
15 5
S S 2a 14d 2a 4d
2 2
?M ?] ?K ?M ?K
?{ ?} ?{ ?} 15 5
16 70 16 20
2 2
?] ?M ?K ?M ?M ?K
= 405-10
= 395
3. If z = x + iy, xy ?? 0 , satisfies the equation
2
z i z 0 ?K?] , then |z
2
| is equal to :
(1) 9
(2) 1
(3) 4
(4)
1
4
Ans. (2)
Sol.
2
2
z iz
z iz
?]?M
?]
|z
2
| = |z|
|z|
2
– |z| = 0
|z|(|z| – 1) = 0
|z| = 0 (not acceptable)
?| |z| = 1
?| |z|
2
= 1
4. Let
i 2 3
ˆ ˆ ˆ
a a i a j a k ?] ?K ?K and
1 2 3
ˆ ˆ ˆ
b b i b j b k ?] ?K ?K be
two vectors such that a 1; ?] a.b 2 ?] and b 4. ?] If
?H ?I c 2 a b 3b ?] ?? ?M , then the angle between b and c
is equal to :
(1)
1
2
cos
3
?M ????
????
????
(2)
1
1
cos
3
?M????
?M????
????
(3)
1
3
cos
2
?M????
?M????
????
????
(4)
1
2
cos
3
?M ????
????
????
Ans. (3)
Page 2
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Tuesday 30
th
January, 2024) TIME : 9 : 00 AM to 12 : 00 NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. A line passing through the point A(9, 0) makes an angle
of 30º with the positive direction of x-axis. If this line is
rotated about A through an angle of 15º in the clockwise
direction, then its equation in the new position is
(1) 9
3 2
?K?]
?M y
x (2) 9
3 2
?K?]
?M x
y
(3) 9
3 2
?K?]
?K x
y (4) 9
3 2
?K?]
?K y
x
Ans. (1)
Sol.
Eq
n
: y – 0 = tan15° (x – 9) ?? y = (2 ?M 3 ?I?@ (x ?M 9)
2. Let S
a
denote the sum of first n terms an arithmetic
progression. If S
20
= 790 and S
10
= 145, then S
15
–
S
5
is :
(1) 395
(2) 390
(3) 405
(4) 410
Ans. (1)
Sol.
?{ ?} 20
20
S 2a 19d 790
2
?] ?K ?]
2a + 19d = 79 …..(1)
?{ ?} 10
10
S 2a 9d 145
2
?] ?K ?]
2a + 9d = 29 …..(2)
From (1) and (2) a = -8, d = 5
?{ ?} ?{ ?} 15 5
15 5
S S 2a 14d 2a 4d
2 2
?M ?] ?K ?M ?K
?{ ?} ?{ ?} 15 5
16 70 16 20
2 2
?] ?M ?K ?M ?M ?K
= 405-10
= 395
3. If z = x + iy, xy ?? 0 , satisfies the equation
2
z i z 0 ?K?] , then |z
2
| is equal to :
(1) 9
(2) 1
(3) 4
(4)
1
4
Ans. (2)
Sol.
2
2
z iz
z iz
?]?M
?]
|z
2
| = |z|
|z|
2
– |z| = 0
|z|(|z| – 1) = 0
|z| = 0 (not acceptable)
?| |z| = 1
?| |z|
2
= 1
4. Let
i 2 3
ˆ ˆ ˆ
a a i a j a k ?] ?K ?K and
1 2 3
ˆ ˆ ˆ
b b i b j b k ?] ?K ?K be
two vectors such that a 1; ?] a.b 2 ?] and b 4. ?] If
?H ?I c 2 a b 3b ?] ?? ?M , then the angle between b and c
is equal to :
(1)
1
2
cos
3
?M ????
????
????
(2)
1
1
cos
3
?M????
?M????
????
(3)
1
3
cos
2
?M????
?M????
????
????
(4)
1
2
cos
3
?M ????
????
????
Ans. (3)
Sol. Given a 1, b 4, a.b 2 ?] ?] ?]
?H ?I c 2 a b 3b ?] ?? ?M
Dot product with a on both sides
c.a 6 ?]?M …..(1)
Dot product with b on both sides
b.c 48 ?]?M …..(2)
2 2
c.c 4 a b 9 b ?] ?? ?K
?H ?I 2 2
2 2 2
c 4 a b a.b 9 b
????
?] ?M ?K ????
????
?H ?I ?H ?I ?H ?I ?H ?I 2 2
c 4 1 4 4 9 16
????
?] ?M ?K ????
????
?{ ?} 2
c 4 12 144 ?]?K
2
c 48 144 ?]?K
2
c 192 ?]
b.c
cos
b c
?| ?? ?]
48
cos
192.4
?M ?| ?? ?]
48
cos
8 3.4
?M ?| ?? ?]
3
cos
2 3
?M ?| ?? ?]
1
3 3
cos cos
2 2
?M????
?M?M
?| ?? ?] ?? ?? ?] ????
????
????
5. The maximum area of a triangle whose one vertex
is at (0, 0) and the other two vertices lie on the
curve y = -2x
2
+ 54 at points (x, y) and (-x, y)
where y > 0 is :
(1) 88
(2) 122
(3) 92
(4) 108
Ans. (4)
Sol.
(x, y)
(-x, y)
(0, 0)
Area of ?d ?@ ?@ 0 0 1
1
x y 1
2
x y 1
?] ?M ?@ ?@ ?H ?I 1
xy xy xy
2
?? ?K ?] ?@ ?@ ?H ?I ?H ?I 2
Area xy x 2x 54 ?d ?] ?] ?M ?K ?@ ?@ ?H ?I ?H ?I 2
d
d
6x 54 0
dx dx
?d ?d ?] ?M ?K ?? ?] ?@ at x = 3
Area = 3 (-2 × 9 + 54) = 108
6. The value of
?H ?I ?H ?I 3 n
2 2 2
n
k 1
n
lim
n k n 3k
?R ????
?] ?K?K
?? is :
(1)
?H ?I 2 3 3
24
?K??
(2)
?H ?I 13
8 4 3 3
?? ?K
(3)
?H ?I 13 2 3 3
8
?M??
(4)
?H ?I 8 2 3 3
?? ?K
Ans. (2)
Sol.
3 n
2 2
n
k 1 4
2 2
n
lim
k 3k
n 1 1
n n
????
?] ?? ?? ?? ?? ?K?K ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
3 n
2 2
n
k 1
2 2
1 n
lim
n
k 3k
1 1
n n
????
?] ?] ?? ?? ?? ?? ?K?K ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
?H ?I 1
2 2
0
dx
1
3 1 x x
3
?] ????
?K?K
????
????
??
Page 3
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Tuesday 30
th
January, 2024) TIME : 9 : 00 AM to 12 : 00 NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. A line passing through the point A(9, 0) makes an angle
of 30º with the positive direction of x-axis. If this line is
rotated about A through an angle of 15º in the clockwise
direction, then its equation in the new position is
(1) 9
3 2
?K?]
?M y
x (2) 9
3 2
?K?]
?M x
y
(3) 9
3 2
?K?]
?K x
y (4) 9
3 2
?K?]
?K y
x
Ans. (1)
Sol.
Eq
n
: y – 0 = tan15° (x – 9) ?? y = (2 ?M 3 ?I?@ (x ?M 9)
2. Let S
a
denote the sum of first n terms an arithmetic
progression. If S
20
= 790 and S
10
= 145, then S
15
–
S
5
is :
(1) 395
(2) 390
(3) 405
(4) 410
Ans. (1)
Sol.
?{ ?} 20
20
S 2a 19d 790
2
?] ?K ?]
2a + 19d = 79 …..(1)
?{ ?} 10
10
S 2a 9d 145
2
?] ?K ?]
2a + 9d = 29 …..(2)
From (1) and (2) a = -8, d = 5
?{ ?} ?{ ?} 15 5
15 5
S S 2a 14d 2a 4d
2 2
?M ?] ?K ?M ?K
?{ ?} ?{ ?} 15 5
16 70 16 20
2 2
?] ?M ?K ?M ?M ?K
= 405-10
= 395
3. If z = x + iy, xy ?? 0 , satisfies the equation
2
z i z 0 ?K?] , then |z
2
| is equal to :
(1) 9
(2) 1
(3) 4
(4)
1
4
Ans. (2)
Sol.
2
2
z iz
z iz
?]?M
?]
|z
2
| = |z|
|z|
2
– |z| = 0
|z|(|z| – 1) = 0
|z| = 0 (not acceptable)
?| |z| = 1
?| |z|
2
= 1
4. Let
i 2 3
ˆ ˆ ˆ
a a i a j a k ?] ?K ?K and
1 2 3
ˆ ˆ ˆ
b b i b j b k ?] ?K ?K be
two vectors such that a 1; ?] a.b 2 ?] and b 4. ?] If
?H ?I c 2 a b 3b ?] ?? ?M , then the angle between b and c
is equal to :
(1)
1
2
cos
3
?M ????
????
????
(2)
1
1
cos
3
?M????
?M????
????
(3)
1
3
cos
2
?M????
?M????
????
????
(4)
1
2
cos
3
?M ????
????
????
Ans. (3)
Sol. Given a 1, b 4, a.b 2 ?] ?] ?]
?H ?I c 2 a b 3b ?] ?? ?M
Dot product with a on both sides
c.a 6 ?]?M …..(1)
Dot product with b on both sides
b.c 48 ?]?M …..(2)
2 2
c.c 4 a b 9 b ?] ?? ?K
?H ?I 2 2
2 2 2
c 4 a b a.b 9 b
????
?] ?M ?K ????
????
?H ?I ?H ?I ?H ?I ?H ?I 2 2
c 4 1 4 4 9 16
????
?] ?M ?K ????
????
?{ ?} 2
c 4 12 144 ?]?K
2
c 48 144 ?]?K
2
c 192 ?]
b.c
cos
b c
?| ?? ?]
48
cos
192.4
?M ?| ?? ?]
48
cos
8 3.4
?M ?| ?? ?]
3
cos
2 3
?M ?| ?? ?]
1
3 3
cos cos
2 2
?M????
?M?M
?| ?? ?] ?? ?? ?] ????
????
????
5. The maximum area of a triangle whose one vertex
is at (0, 0) and the other two vertices lie on the
curve y = -2x
2
+ 54 at points (x, y) and (-x, y)
where y > 0 is :
(1) 88
(2) 122
(3) 92
(4) 108
Ans. (4)
Sol.
(x, y)
(-x, y)
(0, 0)
Area of ?d ?@ ?@ 0 0 1
1
x y 1
2
x y 1
?] ?M ?@ ?@ ?H ?I 1
xy xy xy
2
?? ?K ?] ?@ ?@ ?H ?I ?H ?I 2
Area xy x 2x 54 ?d ?] ?] ?M ?K ?@ ?@ ?H ?I ?H ?I 2
d
d
6x 54 0
dx dx
?d ?d ?] ?M ?K ?? ?] ?@ at x = 3
Area = 3 (-2 × 9 + 54) = 108
6. The value of
?H ?I ?H ?I 3 n
2 2 2
n
k 1
n
lim
n k n 3k
?R ????
?] ?K?K
?? is :
(1)
?H ?I 2 3 3
24
?K??
(2)
?H ?I 13
8 4 3 3
?? ?K
(3)
?H ?I 13 2 3 3
8
?M??
(4)
?H ?I 8 2 3 3
?? ?K
Ans. (2)
Sol.
3 n
2 2
n
k 1 4
2 2
n
lim
k 3k
n 1 1
n n
????
?] ?? ?? ?? ?? ?K?K ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
3 n
2 2
n
k 1
2 2
1 n
lim
n
k 3k
1 1
n n
????
?] ?] ?? ?? ?? ?? ?K?K ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
?H ?I 1
2 2
0
dx
1
3 1 x x
3
?] ????
?K?K
????
????
??
?H ?I ?H ?I 2 2
1
2 2
0
1
x 1 x
1 3 3
dx
1 3 2
1 x x
3
????
?K ?M ?K????
????
?]??
????
?K?K
????
????
??
1
2 2
2 0
1 1 1
dx
2
1 x
1
x
3
????
????
????
?]?M
????
?K ????
????
?K????
????
????????
??
?H ?I ?H ?I 1 1
1 1
0 0
1 1
3 tan 3x tan x
2 2
?M?M
????
?]?M
????
3 1
2 3 2 4 8 2 3
?? ?? ?? ?? ?? ?? ?? ?? ?] ?M ?] ?M ?? ?? ?? ?? ?? ?? ?? ??
?H ?I 13
8. 4 3 3
?? ?] ?K
7. Let g : R R ?? be a non constant twice
differentiable such that
1 3
g' g'
2 2
?? ?? ?? ?? ?] ?? ?? ?? ?? ?? ?? ?? ?? . If a real
valued function f is defined as
?H ?I ?H ?I ?H ?I 1
f x g x g 2 x
2
?] ?? ?K ?M ?? ????
, then
(1) f”(x) = 0 for atleast two x in (0, 2)
(2) f”(x) = 0 for exactly one x in (0, 1)
(3) f”(x) = 0 for no x in (0, 1)
(4)
3 1
f ' f ' 1
2 2
?? ?? ?? ?? ?K?]
?? ?? ?? ?? ?? ?? ?? ??
Ans. (1)
Sol. ?H ?I ?H ?I ?H ?I 3 1
g' g'
g' x g' 2 x 3 2 2
f ' x ,f ' 0
2 2 2
?? ?? ?? ?? ?M ?? ?? ?? ?? ?M?M
????
?? ?? ?? ?? ?] ?] ?] ????
????
Also
1 3
g' g'
1 1 2 2
f ' 0, f ' 0
2 2 2
?? ?? ?? ?? ?M ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?] ?] ?] ?? ?? ?? ?? ?? ?? ?? ??
3 1
f ' f ' 0
2 2
?? ?? ?? ?? ?? ?] ?] ?? ?? ?? ?? ?? ?? ?? ??
1 3
rootsin ,1 and 1,
2 2
?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
?H ?I f " x ?? is zero at least twice in
1 3
,
2 2
????
????
????
8. The area (in square units) of the region bounded by
the parabola y
2
= 4(x – 2) and the line y = 2x - 8
(1) 8
(2) 9
(3) 6
(4) 7
Ans. (2)
Sol. Let X = x – 2
y
2
= 4x, y = 2 (x + 2) – 8
y
2
= 4x, y = 2x – 4
4
2
2
y y 4
A
4 2
?M ?K ?]?M
??
-2
4
= 9
9. Let y = y (x) be the solution of the differential
equation sec x dy + {2(1 – x) tan x + x(2 – x)}
dx = 0 such that y(0) = 2.Then y(2) is equal to :
(1) 2
(2) 2{1 – sin (2)}
(3) 2{sin (2) + 1}
(4) 1
Ans. (1)
Sol. ?H ?I ?H ?I 2
dy
2 x 1 sin x x 2x cos x
dx
?] ?M ?K ?M
Now both side integrate
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2
y x 2 x 1 sin xdx x 2x sin x 2x 2 sin x dx
????
?] ?M ?K ?M ?M ?M????
????
????
?H ?I ?H ?I 2
y x x 2x sin x ?] ?M ?K ??
?H ?I y 0 0 2 ?] ?K ?? ?? ?] ??
?H ?I ?H ?I 2
y x x 2x sin x 2 ?] ?M ?K
?H ?I y 2 2 ?]
Page 4
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Tuesday 30
th
January, 2024) TIME : 9 : 00 AM to 12 : 00 NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. A line passing through the point A(9, 0) makes an angle
of 30º with the positive direction of x-axis. If this line is
rotated about A through an angle of 15º in the clockwise
direction, then its equation in the new position is
(1) 9
3 2
?K?]
?M y
x (2) 9
3 2
?K?]
?M x
y
(3) 9
3 2
?K?]
?K x
y (4) 9
3 2
?K?]
?K y
x
Ans. (1)
Sol.
Eq
n
: y – 0 = tan15° (x – 9) ?? y = (2 ?M 3 ?I?@ (x ?M 9)
2. Let S
a
denote the sum of first n terms an arithmetic
progression. If S
20
= 790 and S
10
= 145, then S
15
–
S
5
is :
(1) 395
(2) 390
(3) 405
(4) 410
Ans. (1)
Sol.
?{ ?} 20
20
S 2a 19d 790
2
?] ?K ?]
2a + 19d = 79 …..(1)
?{ ?} 10
10
S 2a 9d 145
2
?] ?K ?]
2a + 9d = 29 …..(2)
From (1) and (2) a = -8, d = 5
?{ ?} ?{ ?} 15 5
15 5
S S 2a 14d 2a 4d
2 2
?M ?] ?K ?M ?K
?{ ?} ?{ ?} 15 5
16 70 16 20
2 2
?] ?M ?K ?M ?M ?K
= 405-10
= 395
3. If z = x + iy, xy ?? 0 , satisfies the equation
2
z i z 0 ?K?] , then |z
2
| is equal to :
(1) 9
(2) 1
(3) 4
(4)
1
4
Ans. (2)
Sol.
2
2
z iz
z iz
?]?M
?]
|z
2
| = |z|
|z|
2
– |z| = 0
|z|(|z| – 1) = 0
|z| = 0 (not acceptable)
?| |z| = 1
?| |z|
2
= 1
4. Let
i 2 3
ˆ ˆ ˆ
a a i a j a k ?] ?K ?K and
1 2 3
ˆ ˆ ˆ
b b i b j b k ?] ?K ?K be
two vectors such that a 1; ?] a.b 2 ?] and b 4. ?] If
?H ?I c 2 a b 3b ?] ?? ?M , then the angle between b and c
is equal to :
(1)
1
2
cos
3
?M ????
????
????
(2)
1
1
cos
3
?M????
?M????
????
(3)
1
3
cos
2
?M????
?M????
????
????
(4)
1
2
cos
3
?M ????
????
????
Ans. (3)
Sol. Given a 1, b 4, a.b 2 ?] ?] ?]
?H ?I c 2 a b 3b ?] ?? ?M
Dot product with a on both sides
c.a 6 ?]?M …..(1)
Dot product with b on both sides
b.c 48 ?]?M …..(2)
2 2
c.c 4 a b 9 b ?] ?? ?K
?H ?I 2 2
2 2 2
c 4 a b a.b 9 b
????
?] ?M ?K ????
????
?H ?I ?H ?I ?H ?I ?H ?I 2 2
c 4 1 4 4 9 16
????
?] ?M ?K ????
????
?{ ?} 2
c 4 12 144 ?]?K
2
c 48 144 ?]?K
2
c 192 ?]
b.c
cos
b c
?| ?? ?]
48
cos
192.4
?M ?| ?? ?]
48
cos
8 3.4
?M ?| ?? ?]
3
cos
2 3
?M ?| ?? ?]
1
3 3
cos cos
2 2
?M????
?M?M
?| ?? ?] ?? ?? ?] ????
????
????
5. The maximum area of a triangle whose one vertex
is at (0, 0) and the other two vertices lie on the
curve y = -2x
2
+ 54 at points (x, y) and (-x, y)
where y > 0 is :
(1) 88
(2) 122
(3) 92
(4) 108
Ans. (4)
Sol.
(x, y)
(-x, y)
(0, 0)
Area of ?d ?@ ?@ 0 0 1
1
x y 1
2
x y 1
?] ?M ?@ ?@ ?H ?I 1
xy xy xy
2
?? ?K ?] ?@ ?@ ?H ?I ?H ?I 2
Area xy x 2x 54 ?d ?] ?] ?M ?K ?@ ?@ ?H ?I ?H ?I 2
d
d
6x 54 0
dx dx
?d ?d ?] ?M ?K ?? ?] ?@ at x = 3
Area = 3 (-2 × 9 + 54) = 108
6. The value of
?H ?I ?H ?I 3 n
2 2 2
n
k 1
n
lim
n k n 3k
?R ????
?] ?K?K
?? is :
(1)
?H ?I 2 3 3
24
?K??
(2)
?H ?I 13
8 4 3 3
?? ?K
(3)
?H ?I 13 2 3 3
8
?M??
(4)
?H ?I 8 2 3 3
?? ?K
Ans. (2)
Sol.
3 n
2 2
n
k 1 4
2 2
n
lim
k 3k
n 1 1
n n
????
?] ?? ?? ?? ?? ?K?K ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
3 n
2 2
n
k 1
2 2
1 n
lim
n
k 3k
1 1
n n
????
?] ?] ?? ?? ?? ?? ?K?K ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
?H ?I 1
2 2
0
dx
1
3 1 x x
3
?] ????
?K?K
????
????
??
?H ?I ?H ?I 2 2
1
2 2
0
1
x 1 x
1 3 3
dx
1 3 2
1 x x
3
????
?K ?M ?K????
????
?]??
????
?K?K
????
????
??
1
2 2
2 0
1 1 1
dx
2
1 x
1
x
3
????
????
????
?]?M
????
?K ????
????
?K????
????
????????
??
?H ?I ?H ?I 1 1
1 1
0 0
1 1
3 tan 3x tan x
2 2
?M?M
????
?]?M
????
3 1
2 3 2 4 8 2 3
?? ?? ?? ?? ?? ?? ?? ?? ?] ?M ?] ?M ?? ?? ?? ?? ?? ?? ?? ??
?H ?I 13
8. 4 3 3
?? ?] ?K
7. Let g : R R ?? be a non constant twice
differentiable such that
1 3
g' g'
2 2
?? ?? ?? ?? ?] ?? ?? ?? ?? ?? ?? ?? ?? . If a real
valued function f is defined as
?H ?I ?H ?I ?H ?I 1
f x g x g 2 x
2
?] ?? ?K ?M ?? ????
, then
(1) f”(x) = 0 for atleast two x in (0, 2)
(2) f”(x) = 0 for exactly one x in (0, 1)
(3) f”(x) = 0 for no x in (0, 1)
(4)
3 1
f ' f ' 1
2 2
?? ?? ?? ?? ?K?]
?? ?? ?? ?? ?? ?? ?? ??
Ans. (1)
Sol. ?H ?I ?H ?I ?H ?I 3 1
g' g'
g' x g' 2 x 3 2 2
f ' x ,f ' 0
2 2 2
?? ?? ?? ?? ?M ?? ?? ?? ?? ?M?M
????
?? ?? ?? ?? ?] ?] ?] ????
????
Also
1 3
g' g'
1 1 2 2
f ' 0, f ' 0
2 2 2
?? ?? ?? ?? ?M ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?] ?] ?] ?? ?? ?? ?? ?? ?? ?? ??
3 1
f ' f ' 0
2 2
?? ?? ?? ?? ?? ?] ?] ?? ?? ?? ?? ?? ?? ?? ??
1 3
rootsin ,1 and 1,
2 2
?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
?H ?I f " x ?? is zero at least twice in
1 3
,
2 2
????
????
????
8. The area (in square units) of the region bounded by
the parabola y
2
= 4(x – 2) and the line y = 2x - 8
(1) 8
(2) 9
(3) 6
(4) 7
Ans. (2)
Sol. Let X = x – 2
y
2
= 4x, y = 2 (x + 2) – 8
y
2
= 4x, y = 2x – 4
4
2
2
y y 4
A
4 2
?M ?K ?]?M
??
-2
4
= 9
9. Let y = y (x) be the solution of the differential
equation sec x dy + {2(1 – x) tan x + x(2 – x)}
dx = 0 such that y(0) = 2.Then y(2) is equal to :
(1) 2
(2) 2{1 – sin (2)}
(3) 2{sin (2) + 1}
(4) 1
Ans. (1)
Sol. ?H ?I ?H ?I 2
dy
2 x 1 sin x x 2x cos x
dx
?] ?M ?K ?M
Now both side integrate
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2
y x 2 x 1 sin xdx x 2x sin x 2x 2 sin x dx
????
?] ?M ?K ?M ?M ?M????
????
????
?H ?I ?H ?I 2
y x x 2x sin x ?] ?M ?K ??
?H ?I y 0 0 2 ?] ?K ?? ?? ?] ??
?H ?I ?H ?I 2
y x x 2x sin x 2 ?] ?M ?K
?H ?I y 2 2 ?]
?? ?? be the foot of perpendicular from the
point (1, 2, 3) on the line
x 3 y 1 z 4
5 2 3
?K ?M ?K ?]?] .
then ?H ?I 19 ?? ?K ?? ?K ?? is equal to :
(1) 102
(2) 101
(3) 99
(4) 100
Ans. (2)
Sol.
(1, 2, 3)
P( ) ?? ?L?@?? ?L?@??
Let foot P (5k – 3, 2k + 1, 3k – 4) ?@ DR's AP: 5k 4, 2k 1 , 3k 7 ?? ?M ?M ?M ?@ DR's Line: 5, 2, 3 ?? ?@ Condition of perpendicular lines (25k-20) + (4k-2) + (9k – 21)=0
Then
43
k
38
?] ?@ Then ?H ?I 19 ?? ?K ?? ?K ?? =101
11. Two integers x and y are chosen with replacement
from the set {0, 1, 2, 3, ….., 10}. Then the
probability that | x y| 5 ?M?^ is :
(1)
30
121
(2)
62
121
(3)
60
121
(4)
31
121
Ans. (1)
Sol. If x = 0, y = 6, 7, 8, 9, 10
If x = 1, y = 7, 8, 9, 10
If x = 2, y = 8, 9, 10
If x = 3, y = 9, 10
If x = 4, y = 10
If x = 5, y = no possible value
Total possible ways = (5 + 4 + 3 + 2 + 1) × 2
= 30
Required probability ?] 30 30
11 11 121
?] ?? ?@ 12. If the domain of the function
?H ?I ?H ?I ?H ?I 1
1
e
2 x
f x cos log 3 x
4
?M ?M???? ?M ?] ?K ?M ????
????
is
?? ?? [ , ) y ?M?? ?? ?M , then ?? ?K ?? ?K ?? is equal to :
(1) 12
(2) 9
(3) 11
(4) 8
Ans. (3)
Sol.
2 x
1 1
4
?M ?M ?? ??
2 x
1
4
?M ????
–4 ?? 2 – |x| ?? 4
–6 ?? – |x| ?? 2
–2 ?? |x| ?? 6
|x| ?? 6
?? x ?? [–6, 6] …(1)
Now, 3 – x ?? 1
And x ?? 2 …(2)
and 3 – x > 0
x < 3 …(3)
From (1), (2) and (3)
?? x ?? [–6, 3) – {2}
?? = 6
?? = 3
?? = 2
?? + ?? + ?? = 11
13. Consider the system of linear equation x + y + z =
4 ?? , x + 2y + 2 z ?? = 10 ?? , x + 3y + 4 ?? 2
z = ?? 2
+15,
where ?? , R ???? . Which one of the following
statements is NOT correct ?
(1) The system has unique solution if
1
2
???? and
1 ???? , 15
Page 5
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Tuesday 30
th
January, 2024) TIME : 9 : 00 AM to 12 : 00 NOON
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. A line passing through the point A(9, 0) makes an angle
of 30º with the positive direction of x-axis. If this line is
rotated about A through an angle of 15º in the clockwise
direction, then its equation in the new position is
(1) 9
3 2
?K?]
?M y
x (2) 9
3 2
?K?]
?M x
y
(3) 9
3 2
?K?]
?K x
y (4) 9
3 2
?K?]
?K y
x
Ans. (1)
Sol.
Eq
n
: y – 0 = tan15° (x – 9) ?? y = (2 ?M 3 ?I?@ (x ?M 9)
2. Let S
a
denote the sum of first n terms an arithmetic
progression. If S
20
= 790 and S
10
= 145, then S
15
–
S
5
is :
(1) 395
(2) 390
(3) 405
(4) 410
Ans. (1)
Sol.
?{ ?} 20
20
S 2a 19d 790
2
?] ?K ?]
2a + 19d = 79 …..(1)
?{ ?} 10
10
S 2a 9d 145
2
?] ?K ?]
2a + 9d = 29 …..(2)
From (1) and (2) a = -8, d = 5
?{ ?} ?{ ?} 15 5
15 5
S S 2a 14d 2a 4d
2 2
?M ?] ?K ?M ?K
?{ ?} ?{ ?} 15 5
16 70 16 20
2 2
?] ?M ?K ?M ?M ?K
= 405-10
= 395
3. If z = x + iy, xy ?? 0 , satisfies the equation
2
z i z 0 ?K?] , then |z
2
| is equal to :
(1) 9
(2) 1
(3) 4
(4)
1
4
Ans. (2)
Sol.
2
2
z iz
z iz
?]?M
?]
|z
2
| = |z|
|z|
2
– |z| = 0
|z|(|z| – 1) = 0
|z| = 0 (not acceptable)
?| |z| = 1
?| |z|
2
= 1
4. Let
i 2 3
ˆ ˆ ˆ
a a i a j a k ?] ?K ?K and
1 2 3
ˆ ˆ ˆ
b b i b j b k ?] ?K ?K be
two vectors such that a 1; ?] a.b 2 ?] and b 4. ?] If
?H ?I c 2 a b 3b ?] ?? ?M , then the angle between b and c
is equal to :
(1)
1
2
cos
3
?M ????
????
????
(2)
1
1
cos
3
?M????
?M????
????
(3)
1
3
cos
2
?M????
?M????
????
????
(4)
1
2
cos
3
?M ????
????
????
Ans. (3)
Sol. Given a 1, b 4, a.b 2 ?] ?] ?]
?H ?I c 2 a b 3b ?] ?? ?M
Dot product with a on both sides
c.a 6 ?]?M …..(1)
Dot product with b on both sides
b.c 48 ?]?M …..(2)
2 2
c.c 4 a b 9 b ?] ?? ?K
?H ?I 2 2
2 2 2
c 4 a b a.b 9 b
????
?] ?M ?K ????
????
?H ?I ?H ?I ?H ?I ?H ?I 2 2
c 4 1 4 4 9 16
????
?] ?M ?K ????
????
?{ ?} 2
c 4 12 144 ?]?K
2
c 48 144 ?]?K
2
c 192 ?]
b.c
cos
b c
?| ?? ?]
48
cos
192.4
?M ?| ?? ?]
48
cos
8 3.4
?M ?| ?? ?]
3
cos
2 3
?M ?| ?? ?]
1
3 3
cos cos
2 2
?M????
?M?M
?| ?? ?] ?? ?? ?] ????
????
????
5. The maximum area of a triangle whose one vertex
is at (0, 0) and the other two vertices lie on the
curve y = -2x
2
+ 54 at points (x, y) and (-x, y)
where y > 0 is :
(1) 88
(2) 122
(3) 92
(4) 108
Ans. (4)
Sol.
(x, y)
(-x, y)
(0, 0)
Area of ?d ?@ ?@ 0 0 1
1
x y 1
2
x y 1
?] ?M ?@ ?@ ?H ?I 1
xy xy xy
2
?? ?K ?] ?@ ?@ ?H ?I ?H ?I 2
Area xy x 2x 54 ?d ?] ?] ?M ?K ?@ ?@ ?H ?I ?H ?I 2
d
d
6x 54 0
dx dx
?d ?d ?] ?M ?K ?? ?] ?@ at x = 3
Area = 3 (-2 × 9 + 54) = 108
6. The value of
?H ?I ?H ?I 3 n
2 2 2
n
k 1
n
lim
n k n 3k
?R ????
?] ?K?K
?? is :
(1)
?H ?I 2 3 3
24
?K??
(2)
?H ?I 13
8 4 3 3
?? ?K
(3)
?H ?I 13 2 3 3
8
?M??
(4)
?H ?I 8 2 3 3
?? ?K
Ans. (2)
Sol.
3 n
2 2
n
k 1 4
2 2
n
lim
k 3k
n 1 1
n n
????
?] ?? ?? ?? ?? ?K?K ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
3 n
2 2
n
k 1
2 2
1 n
lim
n
k 3k
1 1
n n
????
?] ?] ?? ?? ?? ?? ?K?K ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
?H ?I 1
2 2
0
dx
1
3 1 x x
3
?] ????
?K?K
????
????
??
?H ?I ?H ?I 2 2
1
2 2
0
1
x 1 x
1 3 3
dx
1 3 2
1 x x
3
????
?K ?M ?K????
????
?]??
????
?K?K
????
????
??
1
2 2
2 0
1 1 1
dx
2
1 x
1
x
3
????
????
????
?]?M
????
?K ????
????
?K????
????
????????
??
?H ?I ?H ?I 1 1
1 1
0 0
1 1
3 tan 3x tan x
2 2
?M?M
????
?]?M
????
3 1
2 3 2 4 8 2 3
?? ?? ?? ?? ?? ?? ?? ?? ?] ?M ?] ?M ?? ?? ?? ?? ?? ?? ?? ??
?H ?I 13
8. 4 3 3
?? ?] ?K
7. Let g : R R ?? be a non constant twice
differentiable such that
1 3
g' g'
2 2
?? ?? ?? ?? ?] ?? ?? ?? ?? ?? ?? ?? ?? . If a real
valued function f is defined as
?H ?I ?H ?I ?H ?I 1
f x g x g 2 x
2
?] ?? ?K ?M ?? ????
, then
(1) f”(x) = 0 for atleast two x in (0, 2)
(2) f”(x) = 0 for exactly one x in (0, 1)
(3) f”(x) = 0 for no x in (0, 1)
(4)
3 1
f ' f ' 1
2 2
?? ?? ?? ?? ?K?]
?? ?? ?? ?? ?? ?? ?? ??
Ans. (1)
Sol. ?H ?I ?H ?I ?H ?I 3 1
g' g'
g' x g' 2 x 3 2 2
f ' x ,f ' 0
2 2 2
?? ?? ?? ?? ?M ?? ?? ?? ?? ?M?M
????
?? ?? ?? ?? ?] ?] ?] ????
????
Also
1 3
g' g'
1 1 2 2
f ' 0, f ' 0
2 2 2
?? ?? ?? ?? ?M ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?] ?] ?] ?? ?? ?? ?? ?? ?? ?? ??
3 1
f ' f ' 0
2 2
?? ?? ?? ?? ?? ?] ?] ?? ?? ?? ?? ?? ?? ?? ??
1 3
rootsin ,1 and 1,
2 2
?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ??
?H ?I f " x ?? is zero at least twice in
1 3
,
2 2
????
????
????
8. The area (in square units) of the region bounded by
the parabola y
2
= 4(x – 2) and the line y = 2x - 8
(1) 8
(2) 9
(3) 6
(4) 7
Ans. (2)
Sol. Let X = x – 2
y
2
= 4x, y = 2 (x + 2) – 8
y
2
= 4x, y = 2x – 4
4
2
2
y y 4
A
4 2
?M ?K ?]?M
??
-2
4
= 9
9. Let y = y (x) be the solution of the differential
equation sec x dy + {2(1 – x) tan x + x(2 – x)}
dx = 0 such that y(0) = 2.Then y(2) is equal to :
(1) 2
(2) 2{1 – sin (2)}
(3) 2{sin (2) + 1}
(4) 1
Ans. (1)
Sol. ?H ?I ?H ?I 2
dy
2 x 1 sin x x 2x cos x
dx
?] ?M ?K ?M
Now both side integrate
?H ?I ?H ?I ?H ?I ?H ?I ?H ?I 2
y x 2 x 1 sin xdx x 2x sin x 2x 2 sin x dx
????
?] ?M ?K ?M ?M ?M????
????
????
?H ?I ?H ?I 2
y x x 2x sin x ?] ?M ?K ??
?H ?I y 0 0 2 ?] ?K ?? ?? ?] ??
?H ?I ?H ?I 2
y x x 2x sin x 2 ?] ?M ?K
?H ?I y 2 2 ?]
?? ?? be the foot of perpendicular from the
point (1, 2, 3) on the line
x 3 y 1 z 4
5 2 3
?K ?M ?K ?]?] .
then ?H ?I 19 ?? ?K ?? ?K ?? is equal to :
(1) 102
(2) 101
(3) 99
(4) 100
Ans. (2)
Sol.
(1, 2, 3)
P( ) ?? ?L?@?? ?L?@??
Let foot P (5k – 3, 2k + 1, 3k – 4) ?@ DR's AP: 5k 4, 2k 1 , 3k 7 ?? ?M ?M ?M ?@ DR's Line: 5, 2, 3 ?? ?@ Condition of perpendicular lines (25k-20) + (4k-2) + (9k – 21)=0
Then
43
k
38
?] ?@ Then ?H ?I 19 ?? ?K ?? ?K ?? =101
11. Two integers x and y are chosen with replacement
from the set {0, 1, 2, 3, ….., 10}. Then the
probability that | x y| 5 ?M?^ is :
(1)
30
121
(2)
62
121
(3)
60
121
(4)
31
121
Ans. (1)
Sol. If x = 0, y = 6, 7, 8, 9, 10
If x = 1, y = 7, 8, 9, 10
If x = 2, y = 8, 9, 10
If x = 3, y = 9, 10
If x = 4, y = 10
If x = 5, y = no possible value
Total possible ways = (5 + 4 + 3 + 2 + 1) × 2
= 30
Required probability ?] 30 30
11 11 121
?] ?? ?@ 12. If the domain of the function
?H ?I ?H ?I ?H ?I 1
1
e
2 x
f x cos log 3 x
4
?M ?M???? ?M ?] ?K ?M ????
????
is
?? ?? [ , ) y ?M?? ?? ?M , then ?? ?K ?? ?K ?? is equal to :
(1) 12
(2) 9
(3) 11
(4) 8
Ans. (3)
Sol.
2 x
1 1
4
?M ?M ?? ??
2 x
1
4
?M ????
–4 ?? 2 – |x| ?? 4
–6 ?? – |x| ?? 2
–2 ?? |x| ?? 6
|x| ?? 6
?? x ?? [–6, 6] …(1)
Now, 3 – x ?? 1
And x ?? 2 …(2)
and 3 – x > 0
x < 3 …(3)
From (1), (2) and (3)
?? x ?? [–6, 3) – {2}
?? = 6
?? = 3
?? = 2
?? + ?? + ?? = 11
13. Consider the system of linear equation x + y + z =
4 ?? , x + 2y + 2 z ?? = 10 ?? , x + 3y + 4 ?? 2
z = ?? 2
+15,
where ?? , R ???? . Which one of the following
statements is NOT correct ?
(1) The system has unique solution if
1
2
???? and
1 ???? , 15
(2) The system is inconsistent if
1
2
???] and 1 ????
(3) The system has infinite number of solutions if
1
2
???] and 15 ???]
(4) The system is consistent if
1
2
????
Ans. (2)
Sol. x + y + z = 4 ?? , x + 2y + 2 z ?? = 10 ?? , x + 3y + 4 ?? 2
z = ?? 2
+15,
2
1 1 1
1 2 2
1 3 4
?d ?] ?? ?? = ?H ?I 2
2 1 ???M ?@ ?@ For unique solution
1
0, 2 1 0,
2
????
?d ?? ?? ?M ?? ?? ?? ????
????
Let
1
0,
2
?d ?] ?? ?]
y x z
2
4 1 1
0, 10 2 1
15 3 1
?? ?d ?] ?d ?] ?d ?] ?? ???K
?H ?I ?H ?I 15 1 ?] ?? ?M ?? ?M
For infinite solution
1
, 1 or 15
2
?? ?] ?? ?]
14. If the circles ?H ?I ?H ?I 2 2 2
x 1 y 2 r ?K ?K ?K ?] and
2 2
x y 4x 4y 4 0 ?K ?M ?M ?K ?] intersect at exactly two
distinct points, then
(1) 5 < r < 9
(2) 0 < r < 7
(3) 3 < r < 7
(4)
1
r 7
2
?\?\
Ans. (3)
Sol. If two circles intersect at two distinct points
1 2 1 2 1 2
r r C C r r ?? ?M ?\ ?\ ?K
r 2 9 16 r 2 ?M ?\ ?K ?\ ?K
|r – 2 | < 5 and r + 2 > 5
-5 < r – 2 < 5 r > 3 ……….(2)
-3 < r < 7 ………(1)
From (1) and (2)
3 < r < 7
15. If the length of the minor axis of ellipse is equal to
half of the distance between the foci, then the
eccentricity of the ellipse is :
(1)
5
3
(2)
3
2
(3)
1
3
(4)
2
5
Ans. (4)
Sol. 2b = ae
b e
a 2
?]
2
e
e 1
4
?]?M
2
e
5
?]
16. Let M denote the median of the following
frequency distribution.
Class 0-4 4-8 8-12 12-16 16-20
Frequency 3 9 10 8 6
Then 20 M is equal to :
(1) 416
(2) 104
(3) 52
(4) 208
Ans. (4)
Sol.
Class Frequency Cumulative
frequency
0-4 3 3
4-8 9 12
8-12 10 22
12-16 8 30
16-20 6 36
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