Page 1
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Saturday 27
th
January, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Considering only the principal values of inverse
trigonometric functions, the number of positive
real values of x satisfying
1 1
tan (x) tan (2x)
4
?M?M
?? ?K?]
is :
(1) More than 2
(2) 1
(3) 2
(4) 0
Ans. (2)
Sol.
1 1
tan x tan 2x
4
?M?M
?? ?K?] ; x > 0
?? 1 1
tan 2x tan x
4
?M?M
?? ?]?M
Taking tan both sides
?? 1 x
2x
1 x
?M ?] ?K
2
2x 3x 1 0 ?? ?K ?M ?]
3 9 8 3 17
x
8 8
?M ?? ?K ?M ?? ?]?]
Only possible
3 17
x
8
?M?K
?]
2. Consider the function f :(0,2) R ?? defined by
x 2
f (x)
2 x
?]?K and the function g(x) defined by
min{f (t)}, 0 t x and 0 x 1
g(x) 3
x, 1 x 2
2
?\ ?? ?\ ?? ?? ?? ?] ?? ?K ?\ ?\ ?? ?? . Then
(1) g is continuous but not differentiable at x = 1
(2) g is not continuous for all x (0,2) ??
(3) g is neither continuous nor differentiable at x = 1
(4) g is continuous and differentiable for all x (0,2) ??
Ans. (1)
Sol. f :(0,2) R ?? ;
x 2
f (x)
2 x
?]?K
1 2
f (x)
2 x
?R ?? ?]?M
f (x) ?| is decreasing in domain.
2
2
x
f(x)
x 2
0 x 1
2 x
g(x)
3
x 1 x 2
2
?? ?K ?\ ?? ?? ?] ?? ?? ?K ?\ ?\ ??
1 2 O
g(x)
3. Let the image of the point (1, 0, 7) in the line
x y 1 z 2
1 2 3
?M?M
?]?] be the point ( ?? , ?? , ?? ). Then
which one of the following points lies on the line
passing through ( ?? , ?? , ?? ) and making angles
2
3
??
and
3
4
?? with y-axis and z-axis respectively and an
acute angle with x-axis ?
(1)
?H ?I 1, 2,1 2 ?M?K
(2)
?H ?I 1,2,1 2 ?M
(3)
?H ?I 3,4,3 2 2 ?M
(4)
?H ?I 3, 4,3 2 2 ?M?K
Ans. (3)
Page 2
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Saturday 27
th
January, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Considering only the principal values of inverse
trigonometric functions, the number of positive
real values of x satisfying
1 1
tan (x) tan (2x)
4
?M?M
?? ?K?]
is :
(1) More than 2
(2) 1
(3) 2
(4) 0
Ans. (2)
Sol.
1 1
tan x tan 2x
4
?M?M
?? ?K?] ; x > 0
?? 1 1
tan 2x tan x
4
?M?M
?? ?]?M
Taking tan both sides
?? 1 x
2x
1 x
?M ?] ?K
2
2x 3x 1 0 ?? ?K ?M ?]
3 9 8 3 17
x
8 8
?M ?? ?K ?M ?? ?]?]
Only possible
3 17
x
8
?M?K
?]
2. Consider the function f :(0,2) R ?? defined by
x 2
f (x)
2 x
?]?K and the function g(x) defined by
min{f (t)}, 0 t x and 0 x 1
g(x) 3
x, 1 x 2
2
?\ ?? ?\ ?? ?? ?? ?] ?? ?K ?\ ?\ ?? ?? . Then
(1) g is continuous but not differentiable at x = 1
(2) g is not continuous for all x (0,2) ??
(3) g is neither continuous nor differentiable at x = 1
(4) g is continuous and differentiable for all x (0,2) ??
Ans. (1)
Sol. f :(0,2) R ?? ;
x 2
f (x)
2 x
?]?K
1 2
f (x)
2 x
?R ?? ?]?M
f (x) ?| is decreasing in domain.
2
2
x
f(x)
x 2
0 x 1
2 x
g(x)
3
x 1 x 2
2
?? ?K ?\ ?? ?? ?] ?? ?? ?K ?\ ?\ ??
1 2 O
g(x)
3. Let the image of the point (1, 0, 7) in the line
x y 1 z 2
1 2 3
?M?M
?]?] be the point ( ?? , ?? , ?? ). Then
which one of the following points lies on the line
passing through ( ?? , ?? , ?? ) and making angles
2
3
??
and
3
4
?? with y-axis and z-axis respectively and an
acute angle with x-axis ?
(1)
?H ?I 1, 2,1 2 ?M?K
(2)
?H ?I 1,2,1 2 ?M
(3)
?H ?I 3,4,3 2 2 ?M
(4)
?H ?I 3, 4,3 2 2 ?M?K
Ans. (3)
Sol.
1
x y 1 z 2
L
1 2 3
?M?M
?] ?] ?] ?] ??
M( ,1 2 ,2 3 ) ?? ?K ?? ?K ??
ˆ ˆ ˆ
PM ( 1)i (1 2 )j (3 5)k ?] ?? ?M ?K ?K ?? ?K ?? ?M
PM is perpendicular to line L
1
PM.b 0 ?] (
ˆ ˆ ˆ
b i 2j 3k ?] ?K ?K )
1 4 2 9 15 0 ?? ?? ?M ?K ?? ?K ?K ?? ?M ?]
14 14 1 ?? ?] ?? ?? ?]
M (1,3,5) ?|?]
Q 2M P ?]?M [M is midpoint of P & Q ]
ˆ ˆ ˆ ˆ ˆ
Q 2i 6j 10k i 7k ?] ?K ?K ?M ?M
ˆ ˆ ˆ
Q i 6j 3k ?] ?K ?K
( , , ) (1,6,3) ?| ?? ?? ?? ?]
Required line having direction cosine (l, m, n)
2 2 2
1 ?K ?K ?] l m n
2 2
2
1 1
1
2 2
???? ????
?? ?K ?M ?K ?M ?] ???? ????
???? ????
l
2
1
4
?] l
1
2
?|?] l [Line make acute angle with x-axis]
Equation of line passing through (1, 6, 3) will be
1 1 1
ˆ ˆ ˆ ˆ ˆ ˆ
r (i 6j 3k) i j k
2 2 2
????
?] ?K ?K ?K ?? ?M ?M????
????
Option (3) satisfying for ?? = 4
4. Let R be the interior region between the lines
3x y 1 0 ?M ?K ?] and x 2y 5 0 ?K ?M ?] containing the
origin. The set of all values of a, for which the
points (a
2
, a + 1) lie in R, is :
(1)
1
( 3, 1) ,1
3
????
?M ?M ?? ?M ????
????
(2)
1
( 3,0) ,1
3
????
?M??
????
????
(3)
2
( 3,0) ,1
3
????
?M??
????
????
(4)
1
( 3, 1) ,1
3
????
?M ?M ?? ????
????
Ans. (2)
Sol. P(a
2
, a + 1)
L
1
= 3x – y + 1 = 0
Origin and P lies same side w.r.t. L
1
?? L
1
(0) . L
1
(P) > 0
?| 3(a
2
) – (a + 1) + 1 > 0
y
O
(0,0)
L : x+2y–5=0
2
x
L : 3x–y+1=0
1
?? 3a
2
– a > 0
1
a ( ,0) ,
3
????
?? ?M ?? ?? ?? ????
????
…………….(1)
Let L
2
: x + 2y – 5 = 0
Origin and P lies same side w.r.t. L
2
?? 2 2
L (0).L (P) 0 ?^
2
a 2(a 1) 5 0 ?? ?K ?K ?M ?\
?? 2
a 2a 3 0 ?K ?M ?\
?? (a 3)(a 1) 0 ?K ?M ?\
?| a ( 3,1) ???M …………….(2)
Intersection of (1) and (2)
1
a ( 3,0) ,1
3
????
?? ?M ?? ????
????
Page 3
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Saturday 27
th
January, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Considering only the principal values of inverse
trigonometric functions, the number of positive
real values of x satisfying
1 1
tan (x) tan (2x)
4
?M?M
?? ?K?]
is :
(1) More than 2
(2) 1
(3) 2
(4) 0
Ans. (2)
Sol.
1 1
tan x tan 2x
4
?M?M
?? ?K?] ; x > 0
?? 1 1
tan 2x tan x
4
?M?M
?? ?]?M
Taking tan both sides
?? 1 x
2x
1 x
?M ?] ?K
2
2x 3x 1 0 ?? ?K ?M ?]
3 9 8 3 17
x
8 8
?M ?? ?K ?M ?? ?]?]
Only possible
3 17
x
8
?M?K
?]
2. Consider the function f :(0,2) R ?? defined by
x 2
f (x)
2 x
?]?K and the function g(x) defined by
min{f (t)}, 0 t x and 0 x 1
g(x) 3
x, 1 x 2
2
?\ ?? ?\ ?? ?? ?? ?] ?? ?K ?\ ?\ ?? ?? . Then
(1) g is continuous but not differentiable at x = 1
(2) g is not continuous for all x (0,2) ??
(3) g is neither continuous nor differentiable at x = 1
(4) g is continuous and differentiable for all x (0,2) ??
Ans. (1)
Sol. f :(0,2) R ?? ;
x 2
f (x)
2 x
?]?K
1 2
f (x)
2 x
?R ?? ?]?M
f (x) ?| is decreasing in domain.
2
2
x
f(x)
x 2
0 x 1
2 x
g(x)
3
x 1 x 2
2
?? ?K ?\ ?? ?? ?] ?? ?? ?K ?\ ?\ ??
1 2 O
g(x)
3. Let the image of the point (1, 0, 7) in the line
x y 1 z 2
1 2 3
?M?M
?]?] be the point ( ?? , ?? , ?? ). Then
which one of the following points lies on the line
passing through ( ?? , ?? , ?? ) and making angles
2
3
??
and
3
4
?? with y-axis and z-axis respectively and an
acute angle with x-axis ?
(1)
?H ?I 1, 2,1 2 ?M?K
(2)
?H ?I 1,2,1 2 ?M
(3)
?H ?I 3,4,3 2 2 ?M
(4)
?H ?I 3, 4,3 2 2 ?M?K
Ans. (3)
Sol.
1
x y 1 z 2
L
1 2 3
?M?M
?] ?] ?] ?] ??
M( ,1 2 ,2 3 ) ?? ?K ?? ?K ??
ˆ ˆ ˆ
PM ( 1)i (1 2 )j (3 5)k ?] ?? ?M ?K ?K ?? ?K ?? ?M
PM is perpendicular to line L
1
PM.b 0 ?] (
ˆ ˆ ˆ
b i 2j 3k ?] ?K ?K )
1 4 2 9 15 0 ?? ?? ?M ?K ?? ?K ?K ?? ?M ?]
14 14 1 ?? ?] ?? ?? ?]
M (1,3,5) ?|?]
Q 2M P ?]?M [M is midpoint of P & Q ]
ˆ ˆ ˆ ˆ ˆ
Q 2i 6j 10k i 7k ?] ?K ?K ?M ?M
ˆ ˆ ˆ
Q i 6j 3k ?] ?K ?K
( , , ) (1,6,3) ?| ?? ?? ?? ?]
Required line having direction cosine (l, m, n)
2 2 2
1 ?K ?K ?] l m n
2 2
2
1 1
1
2 2
???? ????
?? ?K ?M ?K ?M ?] ???? ????
???? ????
l
2
1
4
?] l
1
2
?|?] l [Line make acute angle with x-axis]
Equation of line passing through (1, 6, 3) will be
1 1 1
ˆ ˆ ˆ ˆ ˆ ˆ
r (i 6j 3k) i j k
2 2 2
????
?] ?K ?K ?K ?? ?M ?M????
????
Option (3) satisfying for ?? = 4
4. Let R be the interior region between the lines
3x y 1 0 ?M ?K ?] and x 2y 5 0 ?K ?M ?] containing the
origin. The set of all values of a, for which the
points (a
2
, a + 1) lie in R, is :
(1)
1
( 3, 1) ,1
3
????
?M ?M ?? ?M ????
????
(2)
1
( 3,0) ,1
3
????
?M??
????
????
(3)
2
( 3,0) ,1
3
????
?M??
????
????
(4)
1
( 3, 1) ,1
3
????
?M ?M ?? ????
????
Ans. (2)
Sol. P(a
2
, a + 1)
L
1
= 3x – y + 1 = 0
Origin and P lies same side w.r.t. L
1
?? L
1
(0) . L
1
(P) > 0
?| 3(a
2
) – (a + 1) + 1 > 0
y
O
(0,0)
L : x+2y–5=0
2
x
L : 3x–y+1=0
1
?? 3a
2
– a > 0
1
a ( ,0) ,
3
????
?? ?M ?? ?? ?? ????
????
…………….(1)
Let L
2
: x + 2y – 5 = 0
Origin and P lies same side w.r.t. L
2
?? 2 2
L (0).L (P) 0 ?^
2
a 2(a 1) 5 0 ?? ?K ?K ?M ?\
?? 2
a 2a 3 0 ?K ?M ?\
?? (a 3)(a 1) 0 ?K ?M ?\
?| a ( 3,1) ???M …………….(2)
Intersection of (1) and (2)
1
a ( 3,0) ,1
3
????
?? ?M ?? ????
????
5. The 20
th
term from the end of the progression
1 1 3 1
20,19 ,18 ,17 ,...., 129
4 2 4 4
?M is :-
(1) –118
(2) –110
(3) –115
(4) –100
Ans. (3)
Sol.
1 1 3 1
20,19 ,18 ,17 ,......, 129
4 2 4 4
?M
This is A.P. with common difference
1
1 3
d 1
4 4
?] ?M ?K ?] ?M
1 1
129 ,..............,19 ,20
4 4
?M
This is also A.P.
1
a 129
4
?]?M and
3
d
4
?]
Required term =
1 3
129 (20 1)
4 4
????
?M ?K ?M ????
????
1 3
129 15 115
4 4
?] ?M ?M ?K ?M ?] ?M
6. Let
1
f : R R
2
?M ????
?M??
????
????
and
5
g : R R
2
?M????
?M??
????
????
be
defined as
2x 3
f (x)
2x 1
?K ?] ?K and
| x | 1
g(x)
2x 5
?K ?] ?K . Then
the domain of the function fog is :
(1)
5
R
2
????
?M?M
????
????
(2) R
(3)
7
R
4
????
?M?M
????
????
(4)
5 7
R ,
2 4
????
?M ?M ?M????
????
Ans. (1)
Sol.
2x 3 1
f (x) ;x
2x 1 2
?K ?] ?? ?M ?K
| x | 1 5
g(x) ,x
2x 5 2
?K ?] ?? ?M ?K
Domain of f(g(x))
2g(x) 3
f (g(x))
2g(x) 1
?K ?] ?K
5
x
2
???M and
| x | 1 1
2x 5 2
?K ???M
?K
5
x R
2
????
?? ?M ?M ????
????
and x R ??
?| Domain will be
5
R
2
????
?M?M
????
????
7. For 0 < a < 1, the value of the integral
2
0
dx
1 2a cos x a
?? ?M?K
?? is :
(1)
2
2
a
?? ???K
(2)
2
2
a
?? ???M
(3)
2
1 a
?? ?M
(4)
2
1 a
?? ?K
Ans. (3)
Sol.
2
0
dx
I ; 0 a 1
1 2a cos x a
?? ?] ?\ ?\ ?M?K
??
2
0
dx
I
1 2a cos x a
?? ?] ?K?K
??
/2
2
2 2 2 2
0
2(1 a )
2I 2 dx
(1 a ) 4a cos x
?? ?K ?] ?K?M
??
/2
2 2
2 2 2 2
0
2(1 a ).sec x
I dx
(1 a ) .sec x 4a
?? ?K ???]
?K?M
??
/2
2 2
2 2 2 2 2
0
2.(1 a ).sec x
I dx
(1 a ) .tan x (1 a )
?? ?K ???]
?K ?K ?M ??
Page 4
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Saturday 27
th
January, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Considering only the principal values of inverse
trigonometric functions, the number of positive
real values of x satisfying
1 1
tan (x) tan (2x)
4
?M?M
?? ?K?]
is :
(1) More than 2
(2) 1
(3) 2
(4) 0
Ans. (2)
Sol.
1 1
tan x tan 2x
4
?M?M
?? ?K?] ; x > 0
?? 1 1
tan 2x tan x
4
?M?M
?? ?]?M
Taking tan both sides
?? 1 x
2x
1 x
?M ?] ?K
2
2x 3x 1 0 ?? ?K ?M ?]
3 9 8 3 17
x
8 8
?M ?? ?K ?M ?? ?]?]
Only possible
3 17
x
8
?M?K
?]
2. Consider the function f :(0,2) R ?? defined by
x 2
f (x)
2 x
?]?K and the function g(x) defined by
min{f (t)}, 0 t x and 0 x 1
g(x) 3
x, 1 x 2
2
?\ ?? ?\ ?? ?? ?? ?] ?? ?K ?\ ?\ ?? ?? . Then
(1) g is continuous but not differentiable at x = 1
(2) g is not continuous for all x (0,2) ??
(3) g is neither continuous nor differentiable at x = 1
(4) g is continuous and differentiable for all x (0,2) ??
Ans. (1)
Sol. f :(0,2) R ?? ;
x 2
f (x)
2 x
?]?K
1 2
f (x)
2 x
?R ?? ?]?M
f (x) ?| is decreasing in domain.
2
2
x
f(x)
x 2
0 x 1
2 x
g(x)
3
x 1 x 2
2
?? ?K ?\ ?? ?? ?] ?? ?? ?K ?\ ?\ ??
1 2 O
g(x)
3. Let the image of the point (1, 0, 7) in the line
x y 1 z 2
1 2 3
?M?M
?]?] be the point ( ?? , ?? , ?? ). Then
which one of the following points lies on the line
passing through ( ?? , ?? , ?? ) and making angles
2
3
??
and
3
4
?? with y-axis and z-axis respectively and an
acute angle with x-axis ?
(1)
?H ?I 1, 2,1 2 ?M?K
(2)
?H ?I 1,2,1 2 ?M
(3)
?H ?I 3,4,3 2 2 ?M
(4)
?H ?I 3, 4,3 2 2 ?M?K
Ans. (3)
Sol.
1
x y 1 z 2
L
1 2 3
?M?M
?] ?] ?] ?] ??
M( ,1 2 ,2 3 ) ?? ?K ?? ?K ??
ˆ ˆ ˆ
PM ( 1)i (1 2 )j (3 5)k ?] ?? ?M ?K ?K ?? ?K ?? ?M
PM is perpendicular to line L
1
PM.b 0 ?] (
ˆ ˆ ˆ
b i 2j 3k ?] ?K ?K )
1 4 2 9 15 0 ?? ?? ?M ?K ?? ?K ?K ?? ?M ?]
14 14 1 ?? ?] ?? ?? ?]
M (1,3,5) ?|?]
Q 2M P ?]?M [M is midpoint of P & Q ]
ˆ ˆ ˆ ˆ ˆ
Q 2i 6j 10k i 7k ?] ?K ?K ?M ?M
ˆ ˆ ˆ
Q i 6j 3k ?] ?K ?K
( , , ) (1,6,3) ?| ?? ?? ?? ?]
Required line having direction cosine (l, m, n)
2 2 2
1 ?K ?K ?] l m n
2 2
2
1 1
1
2 2
???? ????
?? ?K ?M ?K ?M ?] ???? ????
???? ????
l
2
1
4
?] l
1
2
?|?] l [Line make acute angle with x-axis]
Equation of line passing through (1, 6, 3) will be
1 1 1
ˆ ˆ ˆ ˆ ˆ ˆ
r (i 6j 3k) i j k
2 2 2
????
?] ?K ?K ?K ?? ?M ?M????
????
Option (3) satisfying for ?? = 4
4. Let R be the interior region between the lines
3x y 1 0 ?M ?K ?] and x 2y 5 0 ?K ?M ?] containing the
origin. The set of all values of a, for which the
points (a
2
, a + 1) lie in R, is :
(1)
1
( 3, 1) ,1
3
????
?M ?M ?? ?M ????
????
(2)
1
( 3,0) ,1
3
????
?M??
????
????
(3)
2
( 3,0) ,1
3
????
?M??
????
????
(4)
1
( 3, 1) ,1
3
????
?M ?M ?? ????
????
Ans. (2)
Sol. P(a
2
, a + 1)
L
1
= 3x – y + 1 = 0
Origin and P lies same side w.r.t. L
1
?? L
1
(0) . L
1
(P) > 0
?| 3(a
2
) – (a + 1) + 1 > 0
y
O
(0,0)
L : x+2y–5=0
2
x
L : 3x–y+1=0
1
?? 3a
2
– a > 0
1
a ( ,0) ,
3
????
?? ?M ?? ?? ?? ????
????
…………….(1)
Let L
2
: x + 2y – 5 = 0
Origin and P lies same side w.r.t. L
2
?? 2 2
L (0).L (P) 0 ?^
2
a 2(a 1) 5 0 ?? ?K ?K ?M ?\
?? 2
a 2a 3 0 ?K ?M ?\
?? (a 3)(a 1) 0 ?K ?M ?\
?| a ( 3,1) ???M …………….(2)
Intersection of (1) and (2)
1
a ( 3,0) ,1
3
????
?? ?M ?? ????
????
5. The 20
th
term from the end of the progression
1 1 3 1
20,19 ,18 ,17 ,...., 129
4 2 4 4
?M is :-
(1) –118
(2) –110
(3) –115
(4) –100
Ans. (3)
Sol.
1 1 3 1
20,19 ,18 ,17 ,......, 129
4 2 4 4
?M
This is A.P. with common difference
1
1 3
d 1
4 4
?] ?M ?K ?] ?M
1 1
129 ,..............,19 ,20
4 4
?M
This is also A.P.
1
a 129
4
?]?M and
3
d
4
?]
Required term =
1 3
129 (20 1)
4 4
????
?M ?K ?M ????
????
1 3
129 15 115
4 4
?] ?M ?M ?K ?M ?] ?M
6. Let
1
f : R R
2
?M ????
?M??
????
????
and
5
g : R R
2
?M????
?M??
????
????
be
defined as
2x 3
f (x)
2x 1
?K ?] ?K and
| x | 1
g(x)
2x 5
?K ?] ?K . Then
the domain of the function fog is :
(1)
5
R
2
????
?M?M
????
????
(2) R
(3)
7
R
4
????
?M?M
????
????
(4)
5 7
R ,
2 4
????
?M ?M ?M????
????
Ans. (1)
Sol.
2x 3 1
f (x) ;x
2x 1 2
?K ?] ?? ?M ?K
| x | 1 5
g(x) ,x
2x 5 2
?K ?] ?? ?M ?K
Domain of f(g(x))
2g(x) 3
f (g(x))
2g(x) 1
?K ?] ?K
5
x
2
???M and
| x | 1 1
2x 5 2
?K ???M
?K
5
x R
2
????
?? ?M ?M ????
????
and x R ??
?| Domain will be
5
R
2
????
?M?M
????
????
7. For 0 < a < 1, the value of the integral
2
0
dx
1 2a cos x a
?? ?M?K
?? is :
(1)
2
2
a
?? ???K
(2)
2
2
a
?? ???M
(3)
2
1 a
?? ?M
(4)
2
1 a
?? ?K
Ans. (3)
Sol.
2
0
dx
I ; 0 a 1
1 2a cos x a
?? ?] ?\ ?\ ?M?K
??
2
0
dx
I
1 2a cos x a
?? ?] ?K?K
??
/2
2
2 2 2 2
0
2(1 a )
2I 2 dx
(1 a ) 4a cos x
?? ?K ?] ?K?M
??
/2
2 2
2 2 2 2
0
2(1 a ).sec x
I dx
(1 a ) .sec x 4a
?? ?K ???]
?K?M
??
/2
2 2
2 2 2 2 2
0
2.(1 a ).sec x
I dx
(1 a ) .tan x (1 a )
?? ?K ???]
?K ?K ?M ??
2
/2
2
2
2
0
2
2
2.sec x
.dx
1 a
I
1 a
tan x
1 a
?? ?K ???]
???? ?M ?K????
?K????
??
2
2
I 0
(1 a ) 2
??????
?? ?] ?M????
?M ????
2
I
1 a
?? ?] ?M
8. Let
x
g(x) 3f f (3 x)
3
????
?] ?K ?M ????
????
and f (x) 0 ???? ?^ for all
x (0,3) ?? . If g is decreasing in (0, ?? ) and
increasing in ( ?? , 3), then 8 ?? is
(1) 24
(2) 0
(3) 18
(4) 20
Ans. (3)
Sol.
x
g(x) 3f f (3 x)
3
????
?] ?K ?M ????
????
and f (x) 0 ???? ?^ ?B x ?? (0, 3)
f (x) ?? ?? is increasing function
1 x
g (x) 3 .f f (3 x)
3 3
????
?? ?? ?? ?] ?? ?M ?M ????
????
x
f f (3 x)
3
????
???? ?] ?M ?M ????
????
If g is decreasing in (0, ?? )
g (x) 0 ?? ?\
x
f f (3 x) 0
3
????
???? ?M ?M ?\ ????
????
x
f f (3 x)
3
????
???? ?\?M
????
????
x
3 x
3
?? ?\ ?M
9
x
4
???\
Therefore
9
4
???]
Then
9
8 8 18
4
?? ?] ?? ?]
9. If
e
2
x 0
3 sin x cos x log (1 x)
1
lim
3tan x 3
?? ?K ?? ?K ?? ?K ?M ?] , then
2 ?? – ?? is equal to :
(1) 2
(2) 7
(3) 5
(4) 1
Ans. (3)
Sol.
e
2
x 0
3 sin x cos x log (1 x)
1
lim
3tan x 3
?? ?K ?? ?K ?? ?K ?M ?]
3 2 4 2 3
2
x 0
x x x x x
3 x .... 1 .... x ...
3! 2! 4! 2 3 1
lim
3tan x 3
?? ?? ?? ?? ?? ?? ?? ?K ?? ?M ?K ?K ?? ?M ?K ?K ?M ?M ?M???? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ???]
2
2
2 2
x 0
1
(3 ) ( 1)x x ....
x 1 2 2
lim
3x tan x 3
?? ?? ????
?K ?? ?K ?? ?M ?K ?M ?M ?K????
????
?? ?? ?]
3 0, 1 0 ?? ?? ?K ?] ?? ?M ?] and
1
1
2 2
3 3
?? ?M?M
?]
3, 1 ?? ?? ?] ?M ?? ?]
2 2 3 5 ?? ?? ?M ?? ?] ?K ?]
10. If ?? , ?? are the roots of the equation,
2
x x 1 0 ?M ?M ?]
and
n n
n
S 2023 2024 ?] ?? ?K ?? , then
(1)
12 11 10
2S S S ?]?K
(2)
12 11 10
S S S ?]?K
(3)
11 12 10
2S S S ?]?K
(4)
11 10 12
S S S ?]?K
Ans. (2)
Sol.
2
x x 1 0 ?M ?M ?]
n n
n
S 2023 2024 ?] ?? ?K ??
n 1 n 1 n 2 n 2
n 1 n 2
S S 2023 2024 2023 2024
?M ?M ?M ?M ?M?M
?K ?] ?? ?K ?? ?K ?? ?K ??
n 2 n 2
2023 [1 ] 2024 [1 ]
?M?M
?] ?? ?K ?? ?K ?? ?K ??
n 2 2 n 2 2
2023 [ ] 2024 [ ]
?M?M
?] ?? ?? ?K ?? ??
n n
2023 2024 ?] ?? ?K ??
n 1 n 2 n
S S S
?M?M
?K?]
Put n = 12
11 10 12
S S S ?K?]
Page 5
FINAL JEE –MAIN EXAMINATION – JANUARY, 2024
(Held On Saturday 27
th
January, 2024) TIME : 3 : 00 PM to 6 : 00 PM
MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A
1. Considering only the principal values of inverse
trigonometric functions, the number of positive
real values of x satisfying
1 1
tan (x) tan (2x)
4
?M?M
?? ?K?]
is :
(1) More than 2
(2) 1
(3) 2
(4) 0
Ans. (2)
Sol.
1 1
tan x tan 2x
4
?M?M
?? ?K?] ; x > 0
?? 1 1
tan 2x tan x
4
?M?M
?? ?]?M
Taking tan both sides
?? 1 x
2x
1 x
?M ?] ?K
2
2x 3x 1 0 ?? ?K ?M ?]
3 9 8 3 17
x
8 8
?M ?? ?K ?M ?? ?]?]
Only possible
3 17
x
8
?M?K
?]
2. Consider the function f :(0,2) R ?? defined by
x 2
f (x)
2 x
?]?K and the function g(x) defined by
min{f (t)}, 0 t x and 0 x 1
g(x) 3
x, 1 x 2
2
?\ ?? ?\ ?? ?? ?? ?] ?? ?K ?\ ?\ ?? ?? . Then
(1) g is continuous but not differentiable at x = 1
(2) g is not continuous for all x (0,2) ??
(3) g is neither continuous nor differentiable at x = 1
(4) g is continuous and differentiable for all x (0,2) ??
Ans. (1)
Sol. f :(0,2) R ?? ;
x 2
f (x)
2 x
?]?K
1 2
f (x)
2 x
?R ?? ?]?M
f (x) ?| is decreasing in domain.
2
2
x
f(x)
x 2
0 x 1
2 x
g(x)
3
x 1 x 2
2
?? ?K ?\ ?? ?? ?] ?? ?? ?K ?\ ?\ ??
1 2 O
g(x)
3. Let the image of the point (1, 0, 7) in the line
x y 1 z 2
1 2 3
?M?M
?]?] be the point ( ?? , ?? , ?? ). Then
which one of the following points lies on the line
passing through ( ?? , ?? , ?? ) and making angles
2
3
??
and
3
4
?? with y-axis and z-axis respectively and an
acute angle with x-axis ?
(1)
?H ?I 1, 2,1 2 ?M?K
(2)
?H ?I 1,2,1 2 ?M
(3)
?H ?I 3,4,3 2 2 ?M
(4)
?H ?I 3, 4,3 2 2 ?M?K
Ans. (3)
Sol.
1
x y 1 z 2
L
1 2 3
?M?M
?] ?] ?] ?] ??
M( ,1 2 ,2 3 ) ?? ?K ?? ?K ??
ˆ ˆ ˆ
PM ( 1)i (1 2 )j (3 5)k ?] ?? ?M ?K ?K ?? ?K ?? ?M
PM is perpendicular to line L
1
PM.b 0 ?] (
ˆ ˆ ˆ
b i 2j 3k ?] ?K ?K )
1 4 2 9 15 0 ?? ?? ?M ?K ?? ?K ?K ?? ?M ?]
14 14 1 ?? ?] ?? ?? ?]
M (1,3,5) ?|?]
Q 2M P ?]?M [M is midpoint of P & Q ]
ˆ ˆ ˆ ˆ ˆ
Q 2i 6j 10k i 7k ?] ?K ?K ?M ?M
ˆ ˆ ˆ
Q i 6j 3k ?] ?K ?K
( , , ) (1,6,3) ?| ?? ?? ?? ?]
Required line having direction cosine (l, m, n)
2 2 2
1 ?K ?K ?] l m n
2 2
2
1 1
1
2 2
???? ????
?? ?K ?M ?K ?M ?] ???? ????
???? ????
l
2
1
4
?] l
1
2
?|?] l [Line make acute angle with x-axis]
Equation of line passing through (1, 6, 3) will be
1 1 1
ˆ ˆ ˆ ˆ ˆ ˆ
r (i 6j 3k) i j k
2 2 2
????
?] ?K ?K ?K ?? ?M ?M????
????
Option (3) satisfying for ?? = 4
4. Let R be the interior region between the lines
3x y 1 0 ?M ?K ?] and x 2y 5 0 ?K ?M ?] containing the
origin. The set of all values of a, for which the
points (a
2
, a + 1) lie in R, is :
(1)
1
( 3, 1) ,1
3
????
?M ?M ?? ?M ????
????
(2)
1
( 3,0) ,1
3
????
?M??
????
????
(3)
2
( 3,0) ,1
3
????
?M??
????
????
(4)
1
( 3, 1) ,1
3
????
?M ?M ?? ????
????
Ans. (2)
Sol. P(a
2
, a + 1)
L
1
= 3x – y + 1 = 0
Origin and P lies same side w.r.t. L
1
?? L
1
(0) . L
1
(P) > 0
?| 3(a
2
) – (a + 1) + 1 > 0
y
O
(0,0)
L : x+2y–5=0
2
x
L : 3x–y+1=0
1
?? 3a
2
– a > 0
1
a ( ,0) ,
3
????
?? ?M ?? ?? ?? ????
????
…………….(1)
Let L
2
: x + 2y – 5 = 0
Origin and P lies same side w.r.t. L
2
?? 2 2
L (0).L (P) 0 ?^
2
a 2(a 1) 5 0 ?? ?K ?K ?M ?\
?? 2
a 2a 3 0 ?K ?M ?\
?? (a 3)(a 1) 0 ?K ?M ?\
?| a ( 3,1) ???M …………….(2)
Intersection of (1) and (2)
1
a ( 3,0) ,1
3
????
?? ?M ?? ????
????
5. The 20
th
term from the end of the progression
1 1 3 1
20,19 ,18 ,17 ,...., 129
4 2 4 4
?M is :-
(1) –118
(2) –110
(3) –115
(4) –100
Ans. (3)
Sol.
1 1 3 1
20,19 ,18 ,17 ,......, 129
4 2 4 4
?M
This is A.P. with common difference
1
1 3
d 1
4 4
?] ?M ?K ?] ?M
1 1
129 ,..............,19 ,20
4 4
?M
This is also A.P.
1
a 129
4
?]?M and
3
d
4
?]
Required term =
1 3
129 (20 1)
4 4
????
?M ?K ?M ????
????
1 3
129 15 115
4 4
?] ?M ?M ?K ?M ?] ?M
6. Let
1
f : R R
2
?M ????
?M??
????
????
and
5
g : R R
2
?M????
?M??
????
????
be
defined as
2x 3
f (x)
2x 1
?K ?] ?K and
| x | 1
g(x)
2x 5
?K ?] ?K . Then
the domain of the function fog is :
(1)
5
R
2
????
?M?M
????
????
(2) R
(3)
7
R
4
????
?M?M
????
????
(4)
5 7
R ,
2 4
????
?M ?M ?M????
????
Ans. (1)
Sol.
2x 3 1
f (x) ;x
2x 1 2
?K ?] ?? ?M ?K
| x | 1 5
g(x) ,x
2x 5 2
?K ?] ?? ?M ?K
Domain of f(g(x))
2g(x) 3
f (g(x))
2g(x) 1
?K ?] ?K
5
x
2
???M and
| x | 1 1
2x 5 2
?K ???M
?K
5
x R
2
????
?? ?M ?M ????
????
and x R ??
?| Domain will be
5
R
2
????
?M?M
????
????
7. For 0 < a < 1, the value of the integral
2
0
dx
1 2a cos x a
?? ?M?K
?? is :
(1)
2
2
a
?? ???K
(2)
2
2
a
?? ???M
(3)
2
1 a
?? ?M
(4)
2
1 a
?? ?K
Ans. (3)
Sol.
2
0
dx
I ; 0 a 1
1 2a cos x a
?? ?] ?\ ?\ ?M?K
??
2
0
dx
I
1 2a cos x a
?? ?] ?K?K
??
/2
2
2 2 2 2
0
2(1 a )
2I 2 dx
(1 a ) 4a cos x
?? ?K ?] ?K?M
??
/2
2 2
2 2 2 2
0
2(1 a ).sec x
I dx
(1 a ) .sec x 4a
?? ?K ???]
?K?M
??
/2
2 2
2 2 2 2 2
0
2.(1 a ).sec x
I dx
(1 a ) .tan x (1 a )
?? ?K ???]
?K ?K ?M ??
2
/2
2
2
2
0
2
2
2.sec x
.dx
1 a
I
1 a
tan x
1 a
?? ?K ???]
???? ?M ?K????
?K????
??
2
2
I 0
(1 a ) 2
??????
?? ?] ?M????
?M ????
2
I
1 a
?? ?] ?M
8. Let
x
g(x) 3f f (3 x)
3
????
?] ?K ?M ????
????
and f (x) 0 ???? ?^ for all
x (0,3) ?? . If g is decreasing in (0, ?? ) and
increasing in ( ?? , 3), then 8 ?? is
(1) 24
(2) 0
(3) 18
(4) 20
Ans. (3)
Sol.
x
g(x) 3f f (3 x)
3
????
?] ?K ?M ????
????
and f (x) 0 ???? ?^ ?B x ?? (0, 3)
f (x) ?? ?? is increasing function
1 x
g (x) 3 .f f (3 x)
3 3
????
?? ?? ?? ?] ?? ?M ?M ????
????
x
f f (3 x)
3
????
???? ?] ?M ?M ????
????
If g is decreasing in (0, ?? )
g (x) 0 ?? ?\
x
f f (3 x) 0
3
????
???? ?M ?M ?\ ????
????
x
f f (3 x)
3
????
???? ?\?M
????
????
x
3 x
3
?? ?\ ?M
9
x
4
???\
Therefore
9
4
???]
Then
9
8 8 18
4
?? ?] ?? ?]
9. If
e
2
x 0
3 sin x cos x log (1 x)
1
lim
3tan x 3
?? ?K ?? ?K ?? ?K ?M ?] , then
2 ?? – ?? is equal to :
(1) 2
(2) 7
(3) 5
(4) 1
Ans. (3)
Sol.
e
2
x 0
3 sin x cos x log (1 x)
1
lim
3tan x 3
?? ?K ?? ?K ?? ?K ?M ?]
3 2 4 2 3
2
x 0
x x x x x
3 x .... 1 .... x ...
3! 2! 4! 2 3 1
lim
3tan x 3
?? ?? ?? ?? ?? ?? ?? ?K ?? ?M ?K ?K ?? ?M ?K ?K ?M ?M ?M???? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ???]
2
2
2 2
x 0
1
(3 ) ( 1)x x ....
x 1 2 2
lim
3x tan x 3
?? ?? ????
?K ?? ?K ?? ?M ?K ?M ?M ?K????
????
?? ?? ?]
3 0, 1 0 ?? ?? ?K ?] ?? ?M ?] and
1
1
2 2
3 3
?? ?M?M
?]
3, 1 ?? ?? ?] ?M ?? ?]
2 2 3 5 ?? ?? ?M ?? ?] ?K ?]
10. If ?? , ?? are the roots of the equation,
2
x x 1 0 ?M ?M ?]
and
n n
n
S 2023 2024 ?] ?? ?K ?? , then
(1)
12 11 10
2S S S ?]?K
(2)
12 11 10
S S S ?]?K
(3)
11 12 10
2S S S ?]?K
(4)
11 10 12
S S S ?]?K
Ans. (2)
Sol.
2
x x 1 0 ?M ?M ?]
n n
n
S 2023 2024 ?] ?? ?K ??
n 1 n 1 n 2 n 2
n 1 n 2
S S 2023 2024 2023 2024
?M ?M ?M ?M ?M?M
?K ?] ?? ?K ?? ?K ?? ?K ??
n 2 n 2
2023 [1 ] 2024 [1 ]
?M?M
?] ?? ?K ?? ?K ?? ?K ??
n 2 2 n 2 2
2023 [ ] 2024 [ ]
?M?M
?] ?? ?? ?K ?? ??
n n
2023 2024 ?] ?? ?K ??
n 1 n 2 n
S S S
?M?M
?K?]
Put n = 12
11 10 12
S S S ?K?]
11. Let A and B be two finite sets with m and n
elements respectively. The total number of subsets
of the set A is 56 more than the total number of
subsets of B. Then the distance of the point P(m, n)
from the point Q(–2, –3) is
(1) 10
(2) 6
(3) 4
(4) 8
Ans. (1)
Sol.
m n
2 2 56 ?M?]
n m n 3
2 (2 1) 2 7
?M ?M ?] ??
n 3
2 2 ?] and
m n
2 1 7
?M ?M?]
m n
n 3 and 2 8
?M ?? ?] ?]
n 3 and m n 3 ?? ?] ?M ?]
n 3 and m 6 ?? ?] ?]
P(6,3) and Q(–2, –3)
2 2
PQ 8 6 100 10 ?] ?K ?] ?]
Hence option (1) is correct
12. The values of ?? , for which
3 3
1
2 2
1 1
1 0
3 3
2 3 3 1 0
???K
?? ?K ?] ?? ?K ?? ?K , lie in the interval
(1) (–2, 1)
(2) (–3, 0)
(3)
3 3
,
2 2
????
?M????
????
(4) (0, 3)
Ans. (2)
Sol.
3 3
1
2 2
1 1
1 0
3 3
2 3 3 1 0
???K
?? ?K ?] ?? ?K ?? ?K
7 7
(2 3) (3 1) 0
6 6
???M ?? ?? ?? ?? ?? ?? ?K ?M ?? ?K ?] ?? ?? ?? ?? ?? ?? ?? ??
7 7
(2 3). (3 1). 0
6 6
?? ?? ?? ?K ?K ?? ?K ?]
2
2 3 3 1 0 ?? ?? ?K ?? ?K ?? ?K ?]
2
2 6 1 0 ?? ?? ?K ?? ?K ?]
3 7 3 7
,
2 2
?M ?K ?M ?M ?? ?? ?]
Hence option (2) is correct.
13. An urn contains 6 white and 9 black balls. Two
successive draws of 4 balls are made without
replacement. The probability, that the first draw
gives all white balls and the second draw gives all
black balls, is :
(1)
5
256
(2)
5
715
(3)
3
715
(4)
3
256
Ans. (3)
Sol.
6 9
4 4
15 11
4 4
C C
3
C C 715
???]
Hence option (3) is correct.
14. The integral
8 2
12 6 1 3
3
(x x )dx
1
(x 3x 1) tan x
x
?M ?M ????
?K ?K ?K????
????
?? is
equal to :
(1)
1/3
1 3
3 e
1
log tan x C
x
?M????
????
?K?K
????
????
????
????
(2)
1/2
1 3
3 e
1
log tan x C
x
?M????
????
?K?K
????
????
????
????
(3)
1 3
3 e
1
log tan x C
x
?M????
????
?K?K
????
????
????
????
(4)
3
1 3
3 e
1
log tan x C
x
?M????
????
?K?K
????
????
????
????
Ans. (1)
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