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JEE Advanced 2018: Math Exam Guide

The document describes a multi-part math problem involving lines, circles, and loci. It defines several sets related to pairs of circles tangent to a given line at two points and touching each other. It then asks which statements about the locations of various points relative to the defined sets are true.

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0% found this document useful (0 votes)
61 views19 pages

JEE Advanced 2018: Math Exam Guide

The document describes a multi-part math problem involving lines, circles, and loci. It defines several sets related to pairs of circles tangent to a given line at two points and touching each other. It then asks which statements about the locations of various points relative to the defined sets are true.

Uploaded by

Aman Anand
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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JEE (MAIN + ADVANCED) Examination (2018) (Page # 35)

TM JEE ADVANCED 2018 [PAPER - 2]


Hindi _ [MATHEMATICS]

SECTION 1 (Maximum Marks: 24)


• This section contains SIX (06) questions.
• Each question has FOUR options for correct answer(s). ONE OR MORE THAN ONE of these four
option(s) is (are) correct option(s).
• For each question, choose the correct option(s) to answer the question.
• Answer to each question will be evaluated according to the following marking scheme:
Full Marks : .... If only (all) the correct option(s) is (are) chosen.
Partial Marks : .... If all the four options are correct but ONLY three options are chosen.
Partial Marks : .... If three or more options are correct but ONLY two options are chosen, both of
which are correct options.
Partial Marks : .... If two or more options are correct but ONLY one option is chosen and it is a
correct option.
Zero Marks : 0 If none of the options is chosen (i.e. the question is unanswered).
Negative Marks : .... In all other cases.
• For Example: If first, third and fourth are the ONLY three correct options for a question with
secondoption being an incorrect option; selecting only all the three correct options will result in
+4 marks. Selecting only two of the three correct options (e.g. the first and fourth options),
without selecting any incorrect option (second option in this case), will result in +2 marks.
Selecting only one of the three correct options (either first or third or fourth option) ,without
selecting any incorrect option (second option in this case), will result in +1 marks. Selecting any
incorrect option(s) (second option in this case), with or without selection of any correct option(s)
will result in .2 marks.

1. For any positive integer n, define fn : (0, )  R as


n
1  1 
f (x) =  tan  1   x  j  x  j  1  for all x  (0, ).
n

j1 

   
(Here, the inverse trigonometric function tan–1x assumes values in   ,  
 2 2 
Then, which of the following statement (s) is (are) TRUE ?
5 10

(A)  tan2 fj 0  = 55
  (B)  1  fj' 0  sec2  fj 0 =0
j 1 j1

(C) For any fixed positive integer n, xlim tan  fn  x   = 1


 n
2
(D) For any fixed positive integer n, lim sec  fn  x   = 1
x 
1. fdl h/kukRed i w
. kkZ
a
d n dsfy , ] fn : (0, )  R l Hkhx  (0, ) dsfy , ,
n
 1 
fn(x) =  tan1  1   x  j  x  j  1  ds: i esi fj Hkkf"kr gS
A
j1

    
(; gk¡,i zfr y kse f=kdks.kfer h; Qy u tan–1x dk eku   2 , 2  esekur sgS
)
 
r c,fuEu esl sdkS ul k@dkS ul sdFku l R; gS
@gksa
xs\

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(Page # 36) JEE (MAIN + ADVANCED) Examination (2018)

5 10

(A)  tan2 fj  0 = 55
  (B)  1  fj' 0  sec2  fj 0 = 10
j1 j1

(C) fdl hfuf' pr /kukRed i w d n dsfy , ] xlim


. kkZ
a tan  fn  x   = 1 gS
A
 n

(D) fdl hfuf' pr /kukRed i w d n dsfy , ] xlim


. kkZ
a sec2  fn  x   = 1 gS
A


Sol. D
n   x  j   x  j  1 
1
f (x) =  tan  1   x  j  x  j  1 
n
j1  

n
 1 1 
f (x) =   tan  x  j  tan  x  j  1 
n
j1
fn(x) = tan–1(x + n) – tan–1x
 tan(fn(x)) = tan[tan–1(x + n) – tan–1x]
 x  n  x n
tan(fn(x)) = 1  x x  n  tan(fn(x)) =
  2
1  x  nx
2
 n 
 sec2(fn(x)) = 1 + tan2(fn(x))  sec2(fn(x)) = 1   2 
 1  x  nx 
2
lim sec2  fn  x   = lim 1   n 
x  2  =1
x   1  x  nx 

2. Let T be the line passing the points P(–2, 7) and Q(2,–5). Let F1 be the set of all pairs of circles
(S1, S2) such that T is tangent to S1 at P and tangent to S2 at Q, and also such that S1 and S2 touch
each other at a point, say M. Let E1 be the set representing the locus of M as the pair (S1, S2)
varies in F1. Let the set of all straight line segments joining a pair of distinct points of E1 and
passing through the point R(1,1,) be F2. Let E2 be the set of the mid-points of the line segments
in the set F2. Then, which of the following statment(s) is (are) TRUE ?
4 7
(A) The point (–2,7) lies in E1 (B) The point  ,  does NOT lie in E2
5 5

1   3
(C) The point  ,1  lies in E2 (D) The point  0,  does NOT lie in E1
2   2
2. ekukT , d j s[kkgSt ksfcUnq v ksP(–2, 7) r FkkQ(2,–5) l sgksd j xq t j r hgS
AekukF1 mu l HkhoÙ̀k; q Xeks(S1, S2) dkl eq Pp;
bl i zd kj gSfd T, P i j S1 dhLi ' kZ j s[kk r Fkk Q i j S2 dhLi ' kZ
j s[kk gSA r Fkk bl i zd kj HkhS1 r FkkS2 , d & nw l j sdks, d
fcUnqM i j Li ' kZdj r sgS
At c ; q Xe (S1,S2), F1 esfopfj r (varies) dj r k gSr ksekukfd l eq Pp; E1, fcUnqM dsfcUnq i Fk
dksn' kkZ
r k gS
A ekuk fd E1 dsnksfHkUu&fHkUu fcUnq v ksds; q
Xe dkst ksM+ r hgSeku fd E2, l eq Pp; F2 j s[kk[ k.Mksds e/;
fcUnq
v ksdk l eqPp; gS A r c fuEu esl sdkS ul k@dkS ul sdFku l R; gS @gksaxs
4 7
(A) fcUnq(–2,7), E1 esfLFkr gS
A (B) fcUnq 5 , 5  , E2 esfLFkr ughgS
A
 

1   3
(C) fcUnq 2 ,1  , E2 esfLFkr gS
A (D) fcUnq 0, 2  ,E1 esfLFkr ughgS
A
   
Sol. D

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99, 8003899588
JEE (MAIN + ADVANCED) Examination (2018) (Page # 37)

AP = AQ = AM
Locus of M is a circle having PQ as its diameter
Hence, E1 : (x – 2)(x + 2) + (y – 7)(y + 5) = 0 and x  ±2
Locus of B(midpoint)
is a circle having RC as its diameter

E2 : x(x – 1) + (y – 1)2 = 0

Now, after checking the options, we get (D)

b1 
 
b
3. Let S be the set of all column matrices  2  such that b1, b2, b3  R and the system of equastions
b 
 3
(in real variables)
–x + 2y + 5z = b1
2x – 4y + 3z = b2
x – 2y + 2z = b3
has at least one solutions. Then, which of the following system (s) (in real variables) has (have)
b1 
 
b
at least one solutions for each  2   S ?
b 
 3
(A) x + 2y + 3z = b1, 4y + 5z = b2 and x + 2y + 6z = b3
(B) x + y + 3z = b1, 5x + 2y + 6z = b2 and – 2x – y – 3z = b3
(C) –x + 2y – 5z = b1, 2x – 4y + 10z = b2 and x – 2y + 5z = b3
(D) x + 2y + 5z = b1, 2x + 3z = b2 and x + 4y – 5z = b3
b1 
 
3. ekukS l HkhLr EHk vkOgksb2 
;w dk l eq
Pp; bl i zd kj gSfd b1, b2, b3  R gSr Fkk l ehdj .k fudk; ks(okLr fod pj kses)
b 
 3
–x + 2y + 5z = b1
2x – 4y + 3z = b2
x – 2y + 2z = b3
b1 
 
dsde l sde , d gy gS
A r c] fuEu esl sdkS
u l sfudk; @fudk; ks(okLr fod pj kses) dsi zR; sd b2   S dsfy , de l s
b 
 3
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(Page # 38) JEE (MAIN + ADVANCED) Examination (2018)

de , d gy gksxk@gksa
xs?
(A) x + 2y + 3z = b1, 4y + 5z = b2 r Fkkx + 2y + 6z = b3
(B) x + y + 3z = b1, 5x + 2y + 6z = b2 r Fkk– 2x – y – 3z = b3
(C) –x + 2y – 5z = b1, 2x – 4y + 10z = b2 r Fkkx – 2y + 5z = b3
(D) x + 2y + 5z = b1, 2x + 3z = b2 r Fkkx + 4y – 5z = b3

Sol. A,C,D
We find D = 0 & since no pair of planes are parallel, so there are infinite number of solutions.
Let P1 + P2 = P3
 P1 + 7P2 = 13P3
 b1 + 7b2 = 13b3
(A) D  0  unique solution for any b1, b2, b3
(B) D = 0 but P1 + 7P2  13P3
(C) D = 0 Also b2 = – 2b1, b3 = – b1
Satisfies b1 + 7b2 = 13b3 (Actually all three planes are co-incident)
(D) D  0
1
4. Consider two straight lines, each of which is tangent to both the circles x2 + y2 = and the
2
parabola y2 = 4x. Let these lines intersect at the point Q. consider the ellipse whose center is at
the origin O(0,0) and whose semi - major axis is OQ. If the length of the minor axis of this ellipse
is 2 , Then which of the following statment(s) is (are) TRUE ?
1
(A) For the ellipse, the eccentricity is and the length of the latus rectum is 1
2
1 1
(B) For the ellipse, the eccentricity is and the length of the latus rectum is
2 2
1 1
(C) The area of the region bouded by the ellipse between the lines x  and x = 1 is    2
2 4 2
1
(D) The area of the region bounded by the ellipse between the lines x = and x = 1 is
2

   2
16
1
4. nksl j y j s[kkvksi j fopkj dhft , ] ft l esl si zR; sd oÙ̀k x2 + y2 = r Fkk i j oy ; y2 = 4x nksuksdsl kFkLi ' khZgS A ekuk
2
; sj s[kk, ¡ fcUnqQ i j i zfr PNsn dj r h gS
A , d nh?kZ oÙ̀k i j fopkj dj r sgSft l dk dsUnzew
y fcUnqO(0,0) i j gSr Fkk ft l dh
v) Z&nh?kZv{kOQ gS A; fn bl nh?kZoÙ̀kdhy?kq &v{kdhya ckbZ 2 gSAr c fuEu esl sdkS
ul k@dkSul sdFku l R; gS
@gksa
xs\
1
(A) nh?kZ
oÙ̀k dsfy , ] mRdsUnzrk gSr Fkk ukfHky a
c dhy a
ckbZ1 gS
A
2
1 1
(B) nh?kZ
oÙ̀k dsfy , ] mRdsUnzrk gSr Fkk ukfHky a
c dhy a
ckbZ gS
A
2 2
1 1
(C) j s[kkvks x  r Fkkx = 1 dse/; nh?kZ
oÙ̀k } kj k i fj c) {ks=k dk {ks+
=kQy    2 gSA
2 4 2
1 
(D) j s[kkvks x = r Fkkx = 1 dse/; nh?kZ
oÙ̀k } kj k i fj c) {ks=k dk {ks=kQy    2  gS
A
2 16
Sol. A,C

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JEE (MAIN + ADVANCED) Examination (2018) (Page # 39)

1
Let equation of common tangent is y = mx +
m

1
00
m 1
 =  m4 + m2 – 2 = 0  m = ±1
1  m2 2

Equation of common tangents are y = x + 1 and y = – x – 1


Point Q is (–1,0)
x2 y2
 Equation of ellipse is  =1
1 1/2
1 1 2b2
(A) e = 1 = and LR = =1
2 2 a

(C)

1 1
1 x 1
2  . 1  x2 dx 2

1  x2  sin1 x 
Area 2 =
 2 2 1 / 2
1/ 2

   1      2
= 2      = 2   =
 4  4 8   8 4  4 2

5. Let s,t, r be non - zero complex numbers and L be the set of solutions z = x + iy x, y  R,i   1 
of the equation sz + tz + r = 0, where z = x – iy. Then, which of the following statement (s) is
(are ) TRUE ?
(A) If L has exactly one element, then |s|  |t|
(B) If |s| = |t|, then L has infinitely many elements
(C) The number of elements in L  z : z  1  i  5 is at most 2
(D) If L has more than one element, then L has infinitely many elements

Corporate Office : Motion Education Pvt. Ltd., 394 - Rajeev Gandhi Nagar, Kota
(Page # 40) JEE (MAIN + ADVANCED) Examination (2018)

5. ekuks,t, r v' kwU; l fEeJ l a [ ; k, gSr FkkL l ehdj .k sz + tz + r = 0 dsgy ks z = x + iy  x, y  R,i  1  dk


l eq
Pp; gS ] t gk¡ z = x – iy gS A r c] fuEu esl sdkSul k@dkS
ul sdFku l R; gS
@gksa
xs\
(A) ; fn L dk ds oy , d vo; o gS ] r c |s|  |t|
(B) ; fn |s| = |t| gS , r c L dsvU kUr vo; o gS
A
(C) L  z : z  1  i  5
esvo; oksdhl a [ ; k vf/kd l svf/kd 2 gS
A
(D) ; fn L ds, d l svf/kd vo; o gS
] r c L dsvuUr vo; o gS A

Sol. Given
sz  tz  r  0 ......(1)
on taking conjugate sz  tz  r  0 .....(2)
from (1) and (2) elliminating z


z s
2
 t
2
 = r t  rs
(A) = If |s|  |t| then z has unique value
(B) If |s| = |t| then r t  rs may or may not be zero so L may be empty set
(C) locus of z is noll set or singleton set or a line in all cases it will intersect given circle at most
two points.
(D) In this case locus of z is a line so L has infinite elements

f  x  sin t  f  t  sin x
6. Let f : (0,)  R be a twice differentiable function such that lim = sin2x for all
t x tx
x  (0, ).
  
If f   =  , then which of the following statement (s) is (are) TRUE ?
6 12

 
(A) f   =
4 4 2

x4
(B) f(x) <  x2 for all x  (0,)
6
(C) There exists   (0,) such that f'() = 0
 
(D) f "    f   = 0
2
  2

f  x  sin t  f  t  sin x
6. ekukf : (0,)  R , d nq
xq
ukvody uh; Qy u bl i zd kj gSfd l Hkhx  (0, ) dsfy , lim
t x tx
= sin x 2
gS
A
   
; fn f  6  =  gS
, r c fuEu esl sdkS
ul k@dkS
ul sdFku l R; gS
@gksa
xs\
  12

 
(A) f   =
4 4 2

x4
(B) l Hkhx  (0,) dsfy , f(x) <  x2
6
(C)   (0,) bl i zd kj fo| eku gSfd f'() = 0 gS
A
 
(D) f "    f   = 0
2 2

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JEE (MAIN + ADVANCED) Examination (2018) (Page # 41)

Sol. B,C,D
f  x  sin t  f  t  sin x
lim   sin2 x
xx tx
by using L Hopital
f  x  cos t  f '  t  sin x
lim   sin2 x  f(x) cos x - f’(x) sin x = sin2x
xx 1

 f '(x) sin x  f(x) cos x 


   1
 sin2 x 

 f x  
 d  sin x   1
 

f x
 xc
sin x

   
Put x = & f   
6 6 12
 c=0  f(x) = –x sin x
    1
(A) f   
4 4 2
(B) f(x) = – x sin x
x3 x4 x4
as sin x > x – , x sin x  x2   f  x   x 2  x  0,  
6 6 6
(C) f’(x) = – sin x –x cos x
f’(x) =0  tan x = –x  there exist
  0,   for which f’(  ) = 0

(D) f’’ (x) = – 2 cos x + xsinx


     
f ''    , f      f ''    f   0
2 2 2 2 2 2

SECTION 2 (Maximum Marks: 24)


• This section contains EIGHT (08) questions. The answer to each question is a NUMERICAL
VALUE.
4 For each question, enter the correct numerical value (in decimal notation, truncated/
rounded.off to the second decimal place; e.g. 6.25, 7.00, .0.33, ..30, 30.27, .127.30) using
the mouse and the onscreen virtual numeric keypad in the place designated to enter the
answer.
• Answer to each question will be evaluated according to the following marking scheme:
Full Marks : ..3 If ONLY the correct numerical value is entered as answer.
Zero Marks : 0 In all other cases.

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(Page # 42) JEE (MAIN + ADVANCED) Examination (2018)


2
1 3
7. The value of the integral  1
dx
is
0
 x  1 2 6 4
1  x  

2
1 3
7. l ekdy u  1
dx
dk eku gS
A
0
 x  1 2
1  x  6 4

Sol. 2
1 1
2 1  3  2 1  3  dx
 1/ 4
dx
  1/ 4
0
 x  1 1  x 
2 6
 0
 1  x  1  x
2
2 4

 12 
 1 
=  0
dx  1  3  


1  x  2
1  x  
put x = sin 

 6 
 cos d 
=  0 cos  1  sin   
1 3  
 
 

 6 
 1  sin  d 
=  0 cos2  
1 3  
 
 

 6 
6

 
= 
0
sec 2
 d   
0
tan  sec d   1 3  
 
 

 
 6 6

tan  |  sec  |  1  3
= 0 0
 
 

1  2 
=   1
3  3 

=  3 1  3 1 
2
=  3 1 = 2

8. Let P be a matrix of order 3 × 3 such that all the entries in P are from the set {–1, 0 , 1}. Then,
the maximum possible value of the determinant of P is ........
8. ekukP dksfV 3 × 3 dk, d vkO
;w
g bl i zd kj gSfd P esfLFkr l Hkhi zfof"V; k¡l eq
Pp; {–1, 0 , 1} l sgS
A r c P dsl kj f.kd
dk vf/kdr e l a
Hka
o eku gksxk&
Sol. 4
Set A = {-1,0,1}

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for obtaining the determinant having maximum possible value


aii  min{1, 0,1}
aij  max{1, 0,1}

 1 1 1 
 
1 1 1 
Matrix p = 
 1 1 1

p  1 1  1   1  1  1 1  1

p 4
which is maximum possible value.

9. Let X be a set with exactly 5 elements and Y be a set with exactly 7 elements. If  is the number
of one - one functions from X to Y and  is the number of onto functions from Y to X, then the
1
value of
5!
    is ..........
9. ekukX , d l eq
Pp; gSft l dsBhd 5 vo; o gSr Fkk Y , d l eq
Pp; gSft l dsBhd 7 vo; o gS
A; fn , X l sY r c , dS
dh
1
Qy uksdhl a
[ ; k gSr Fkk  ,Y l sX r d dsvkPNknd Qy uksdhl a
[ ; k gS
, rc     dk eku gS
A
5!
Sol. 119
n(X) =5
n(Y) =7
  Number of one-one function = 7 C5  5!
  Number of onto funtion Y to X

a1 b1
a2 b2

a7 b7

1,1,1,1,3 1,1,1,2,2

7! 7!
 5! 3
 5!
3! 4! 2!  3!
=  7

C3  3.7 C3 5!  4  7C3  5!


 4 7 C3 7 C5  4  35  21  119
5!

10. Let f : R  R be a differentiable function with f(0) = 0. If y = f(x) satisfies the differentiable
equation
dy f  x  is
= (2 + 5y)(5y – 2), then the value xlim
dx 

10. ekuk f : R  R , d vody uh; Qy u gSt gk¡ f(0) = 0 gS


A ; fn y = f(x), vody l ehdj .k
dy f  x  dk eku gS
= (2 + 5y)(5y – 2) dksl a
rq , r c xlim
"V dj r k gS &
dx 

Sol. 0.4
dy
 25y2  4
dx

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dy
so,  dx
25y2  4

2
y
1 1 5 xc
 n
Integrating, 25 2 2
2 y
5 5

5y  2
 n  20  x  c 
5y  2
Now, c = 0 as f(0) = 0
5y  2
 e 
20x
Hence
5y  2

5f  x   2
 lim e
20x 
lim
x  5f  x   2 x 

Now, RHS =0  xlim



5f  x   2  0
2
 lim f(x) 
x  5

11. Let f : R  R be a differentiable function wich f(0) = 1 and satisfying the equation
f(x + y) = f(x) f'(y) + f'(x)f(y) for all x, y  R Then, the value of loge(f(4)) is ......
11. ekukf : R  R , d vody uh; Qy u gSt gk¡f(0) = 1 r Fkk l ehdj .k f(x + y) = f(x) f'(y) + f'(x)f(y)
dksl Hkh x, y  R dsfy , l a
rq
"V dj r k gS
] r c loge(f(4)) dk eku gS
A
Sol. 2
P(x,y) : f(x+y) = f(x) f’(y) + f’(x) f(y)  x,y  R
P(0,0) : f(0) = f(0) f’(0)+f’ (0) f(0)
 1= 2f’(0)
1
 f’(0) =
2
P(x,0) : f(x) = f(x). f’(0) + f’(x) . f(0)
1
 f(x) = f(x)  f '(x)
2
1
 f '(x)  f(x)
2
1
x
 f(x)  e2

 In (f(4))=2

12. Let P be a point int he first octant, whose image Q in the plane x + y = 3 ( that is, the line
segment PQ is perpendicualr to the plane x + y = 3 and the mid - point of PQ lies in the plane x
+ y = 3) lies on the z - axis. Let the distance of P from the x - axis be 5. If R is the imags of P in
the xy - plane, then the length of PR is ......
12. ekuk P i zFke v"Bka
' k (octant) es, d fcUnqgS, ft l dk i z
fr fca
c Q l er y x + y = 3 es( vFkkZ r ~] j s[kk[ k.M PQ l er y
x + y = 3 dsy a cor ~gSr Fkk PQ dk e/; fcUnql er y x + y = 3 esfLFkr gS ) z -v{k i j fLFkr gSA ekuk P dhx - v{k
l snw
j h5 gS A; fn R, xy l er y esP dk i zfr fca
c gS ] r c PR dhy a ckbZgS
A

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Sol. 8
Let

P  , ,  
Q 0, 0,   &
R  ,,   

  
Now, PQ || ˆi  ˆj  ˆi  ˆj || ˆi  ˆj 

Also, mid point of PQ lies on the plane
 
  3
2 2
    =6
 = 3
Now, distance of point P from X- axis is 2   2  5

 2  2  25

  2  16
as     3
as   4
Hence, PR = 2  =8

13. Consider the cube in the first octant with sides OP, OQ and OR of length 1, along the x-axis,
1 1 1
y - axis, and z- axis, respectively, where O(0,0,0) is the origin, Let S  , ,  be the centre of
2 2 2
the cube and T be the vertex of the cube opposite to the origin O such that S lies on the diagonal
           
OT. If p = SP , q = SQ , r = SR and t = ST , then the value 
alue of p  q  r  t is ..... 
13. i zFke vkW
DVsa
V (octant)es, d ?ku i j fopkj dhft , ft l dhHkq
t kvks OP, OQ r FkkOR dhy a
ckbZ1 gSr Fkkt ksØe' kx-v{k,
1 1 1
y- v{k, r Fkkz- v{k dsvuq
fn' k gS
, t gk¡O(0,0,0) ew A ekuk S  2 , 2 , 2  , ?ku dk dsUnzgSr Fkk T ew
y fcUnqgS y fcUnqO ds
 
       
l Eeq
[ k ?ku dk ' kh"kZbl i zd kj gSfd S,fod.kZ OT i j fLFkr gS
A ; fn p = SP , q = SQ , r = SR r Fkk t = ST
   
, r c p  q  r  t  dk eku gS&
gS
Sol. (0.5)

T
S

O y
Q

P
x

   1 1 1 1 ˆ ˆ ˆ
p  SP   ,  ,   
2 2 2 2
i  jk  
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   1 1 1 1 ˆ ˆ ˆ
q  SQ    , ,   
 2 2 2 2
i  j  k  
   1 1 1 1 ˆ ˆ ˆ
r  SR    ,  ,  
 2 2 2 2
i  j  k  
   1 1 1  1
t  ST   , ,  
2 2 2 2
ˆ
ˆi  ˆj  k  
ˆi ˆ
ˆj k ˆi ˆj kˆ
    1 1
 
p  q   r  t  4 1  1  1  4  1  1 1
1 1 1 1 1 1

1 ˆ
k 1
16

2ˆi  2ˆj   2ˆi  2ˆj  
2

2

2 2 2 2
14. Let X =  10
C1  + 2  10
C2  + 3  10
C3  + ..... 10  10
C10  .

1
where 10
Cr, r {1,2,.....10} denote binomial coefficient. Then, the value of X is ____
1430
2 2 2 2
14. ekukX =  10
C1  + 2  10
C2  + 3  10
C3  + .....+ 10  10
C10  gS
,

1
t gk¡ 10Cr, r {1,2,.....10} f} i } xq
. kka
d dksn' kkZ
r k gS
] rc X dk eku gS&
1430
Sol. (646)
n
n 2
x  r.( C ) ;n  10
r 0
r

n
x  n. (n Cr )n1Cr 1
r 0

n
x  n. n Cnr .n1Cr 1
r 1

x  10.19 C9
x 1 19
 . C9
1430 143
x  n.2n1 Cn1;n  10
= 646

SECTION 3 (Maximum Marks: 12)


• This section contains FOUR (04) questions.
• Each question has TWO (02) matching lists: LIST.I and LIST.II.
• FOUR options are given representing matching of elements from LIST.I and LIST.II. ONLY
ONE of these four options corresponds to a correct matching.
• For each question, choose the option corresponding to the correct matching.
• For each question, marks will be awarded according to the following marking scheme:
Full Marks : ..3 If ONLY the option corresponding to the correct matching is chosen.
Zero Marks : 0 If none of the options is chosen (i.e. the question is unanswered).
Negative Marks : ..1 In all other cases.

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 x     x  
15. Let E1 = x  R : x  1 and  0 and E = x  E1 : sin1  loge    is real number  .
 x 1  2
   x  1  
  
(Here, the inverse trigonometric function sin–1x assumes values in  ,  )
 2 2
 x 
Let f : E1  R be the function defined by f(x) = loge  
 x  1

1   x 
and g : E2  R be the function defined by g(x) = sin  loge   .
  x  1
List - I List - II
 1   e 
P. The range of f is 1.  , 1  e    e  1 ,  
   
Q. The range of g contains 2. (0,1)
 1 1
R. The domain of f contains 3.  2 , 2 
 
S. The domain of g is 4.  , 0   0,  
 e 
5.  , e  1 
 
1 e 
6.  , 0    ,
 2 e  1 
The correct option is :
(A) P  4; Q  2; R  1; S  1
(B) P  3; Q  3; R  6; S  5
(C) P  4; Q  2; R  1; S  6
(D) P  4; Q  3; R  6; S  5
 x   1     x   
15. ekukE1 = x  R : x  1 r Fkk x  1  0  r FkkE2 = x  E1 : sin  loge  x  1   , d okLr fod l a[; k gS
.
      
  
(; gk¡, i zfr y kse f=kdks.kfer h; Qy u sin–1x dk eku  2 , 2 esekur sgS
)
 
  x
ekukf : E1  R, f(x) = loge  x  1  } kj k i fj Hkkf"kr Qy u gS
A
 
   x 
r Fkkg : E2  R, g(x) = sin1  loge   } kj k i fj H
kkf"kr Qy u gS
A
x  1
  
lw
ph- I lw
ph- II
 1   e 
P. f dk i fj l j gS
& 1.  , 1  e    e  1 ,  
   
Q. g dk i fj l j j [ kr k gS& 2. (0,1)
 1 1
R. f dk i zkUr j [ kr k gS
& 3.  2 , 2 
 
S. g dk i zkUr gS
& 4.  , 0   0,  
 e 
5.  , e  1 
 

1 e 
6.  , 0    , 
 2 e  1

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l ghfodYi gksxk&
(A) P  4; Q  2; R  1; S  1
(B) P  3; Q  3; R  6; S  5
(C) P  4; Q  2; R  1; S  6
(D) P  4; Q  3; R  6; S  5

Sol. (A)
x
E1 : 0
x 1
+

0 1

 E1 : x   , 0   1,  

 x 
E2: 1  n   1
 x  1

1  x 
 e
e  x  1 

x 1
Now  0
x 1 e


 e  1 x  1  0
e  x  1
+

-1/(e-1) 1

 1 
 x   ,   1,  
 1  e

x
also  e  0
x 1
 e  1 x  e  0
x 1
+

1 e/(e-1)

 e 
 x   ,1   , 
 e  1 

 1   e 
So E2 :  ,  , 
 1  e   e  1 
x
as Range of is R +- {1}
x 1
 Range of f is R - {0} or  , 0  0,  

        
Range of g is  ,  \{0} or   , 0    0, 
 2 2  2   2
Now P  4, Q  2, R  1, S  1
Hence A is correct

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16. In a high school, a commintee has to be formed from a group of 6 boys M1, M2, M3, M4, M5, M6 and
5 girls G1, G2, G3, G4, G5.
(i) Let 1 be the total number of ways in which of the commitee can be formed such that the
commitee has 5 members, having exactly 3 boys and 2 girls.
(ii) Let 2 be the total number of ways in which the commitee can be formed such that the
committee has at least 2 members, and having an equal number of bosy and girls.
(iii) Let 3 be the total number of ways in wihc the committee can be formed such that the
commitee has 5 members, at least 2 of them being girls.
(iv) Let 4 be the total number of ways in which the committee can be formed such that the
committee has 4 members, having at least 2 girls and such that both M1 and G1 are NOT in the
committee together.

List - I List - II
P. The value of 1 is 1. 136
Q. The value of 2 is 2. 189
R. The value of 3 is 3. 192
S. The value of 4 is 4. 200
5. 381
6. 461

The correct option is :


(A) P  4 ; Q  6; R  2; S  1
(B) P  1 ; Q  4; R  2; S  3
(C) P  4 ; Q  6; R  5; S  2
(D) P  4 ; Q  2; R  3; S  1
16. , d mPPkfo| ky ; es]6 y M+
d ksM1, M2, M3, M4, M5, M6 r Fkk5 y M+
fd; ksG1, G2, G3, G4, G5 ds, d l ew
g esl s, d l ehfr
cuk; ht kr h gS A
(i) ekuk1 dq y r j hdksdhl a [ ; k gSft l esl fefr bl i zd kj l scuk; ht k l dr hgSfd l fefr es5 l nL; gSft uesl sBhd
3 y M+d sr Fkk 2 y M+ fd; k¡ gS
A
(ii) ekuk2 dq y r j hdksdhl a [ ; k gSft l esl fefr bl i zd kj l scuk; ht k l dr hgSfd l fefr esU; w ur e 2 l nL; gksr Fkk
y M+d sr Fkk y M+
fd; ksdhl a [ ; k cj kcj gksA
(iii) ekuk3 dq y r j hdksdhl a [ ; k gSft l esl fefr bl i zd kj l scuk; ht k l dr hgSfd l fefr es5 l nL; gS sft l esde
l sde 2 y M+ fd; k¡ gksA
(iv) ekuk4 dq y r j hdksdh l a [ ; k gSft l esl fefr bl i zd kj l scuk; h t k l dr h gSfd l fefr ess4 l nL; gSs] ft uesl s
U; w
ur e 2 y M+ fd; k¡ gksr Fkk M1 r FkkG1 nksuksl fefr esl kFk&l kFk u gksA

lw
ph- I lw
ph- II
P. 1 dk eku gS
A 1. 136
Q. 2 dk eku gS
A 2. 189
R. 3 dk eku gS
A 3. 192
S. 4 dk eku gS
A 4. 200
5. 381
6. 461

l ghfodYi gS:
(A) P  4 ; Q  6; R  2; S  1
(B) P  1 ; Q  4; R  2; S  3
(C) P  4 ; Q  6; R  5; S  2
(D) P  4 ; Q  2; R  3; S  1

Sol. (C)
 6  5 
(1) 1       200
3   2
So P  4
(2)

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(Page # 50) JEE (MAIN + ADVANCED) Examination (2018)

 6   5   6   5   6   5   6  5   6   5 
2                         
1   1   2   2   3   3   4   4   5   5 

11
   1
5 
= 46!
So Q  6
 5   6  5   6  5   6   5   6 
(3) 3                    
 2   3   3   2   4  1   5   0 

 11   5   6   5   6 
=          
 5   0   5  1   4 
= 381
So R  5
 5   6   4  5   5   6   4  1  5 
(4) 2                       
 2   2  1  1   3  1   2   1   4 
= 189
= So S  2

x2 y2
17. Let H :   1 , where a > b > 0, be a hyperbola in xy - plane whose conjugate axis LM
2
a b2
subtends an angle of 60° at one of its vertices N. Let the area of the trignale LMN be 4 3 .
List - I List - II
P. The length of the conjugate axis of H is 1. 8
4
Q. The eccentricity of H is 2.
3

2
R. The distance between the foci of H is 3.
3
S. The length of the latus rectum of H is 4. 4

The correct option is :


(A) P  4; Q  2 ; R  1; S  3
(B) P  4; Q  3 ; R  1; S  2
(C) P  4; Q  1 ; R  3; S  2
(D) P  3; Q  4 ; R  2; S  1

x2 y2
17. ekukH :   1 gS
,t gk¡a > b > 0 gS
, xy -l er y es, d vfr i j oy ; gSft l dhl a
;q
Xehv{kLM bl ds' kh"kksZN
a2 b2
esl s, d i j 60° dk , d dks.k cukr h gS
A ekuk f=kHkq
t LMN dk {ks=kQy 4 3 gS
A
lw
ph- I lw
ph- II
P. H dhl a
;q
Xehv{k dhy a
ckbZgS
& 1. 8
4
Q. H dhmRdsUnzrk gS
& 2.
3

2
R. H dhukfHk; ksdse/; nw
j hgS
A 3.
3
S. H dsukfHky a
c dh y a
ckbZgS
& 4. 4

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99, 8003899588
JEE (MAIN + ADVANCED) Examination (2018) (Page # 51)

l ghfodYi gS
&:
(A) P  4; Q  2 ; R  1; S  3
(B) P  4; Q  3 ; R  1; S  2
(C) P  4; Q  1 ; R  3; S  2
(D) P  3; Q  4 ; R  2; S  1
Sol. (B)
L
300

30 0
O a 300 N

b
tan 300 =
a ab 3
1
Now area of LMN  .2b.b 3  4 3  3b2
2
b2 2
 b=2 & a = 2 3  e  1

a2 3
P. Length of conjugate axis = 2b = 4
So P  4
2
Q. Eccentricity e 
3
So Q  3
R. Distance between foci = 2 ae
 2 

2 2 3  
 3
8
So R  1
2
2b2 2 2  4
S. Length of latus rectum =  
a 2 3 3
So S  2

  
     1, e 2  2 
18. Let f1 : R  R, f2 :  ,   R; f3 : 
 2 2   R and f4 : R  R be functions defined by
 
  x2 
(i) f1(x) = sin  1  e 
 
 sin x
 if x  0
1
(ii) f2(x) =  tan x , where the inverse trigonometric function tan–1x assumes values in
 1 if x  0

  
 2 ,2,
 
(iii) f3(x) = [sin(loge(x +2))], where for t  R, [t] denotes the greates integer less than or equal
to t,

 2 1
 x sin   if x  0
(iv) f4(x) =  x
 0 if x  0

Corporate Office : Motion Education Pvt. Ltd., 394 - Rajeev Gandhi Nagar, Kota
(Page # 52) JEE (MAIN + ADVANCED) Examination (2018)

List - I List - II
P. The function f1 is 1. NOT continuous at x = 0
Q. The function f2 is 2. Continuous at x = 0 and NOT differentiable at
x=0
R. The function f3 is 3. differentiable at x = 0 and its derivative is NOT
continuous at x = 0
S. The function f4 is 4. differentiable at x = 0 and its derivative is
continuous at x = 0

The correct option is :


(A) P  2, Q  3; R  1; S  4
(A) P  4, Q  1; R  2; S  3
(A) P  4, Q  2; R  1; S  3
(A) P  2, Q  1; R  4; S  3
  
     1, e 2  2 
18. ,
ekukf1 : R  R, f2 :  2 2   R; f3 :  r Fkkf4 : R  R fuEu } kj k i fj Hkkf"kr Qy u gS
&
   R
 

  x2 
(i) f1(x) = sin  1  e 
 

 sin x
 1
; fn x  0    
(ii) f2(x) =  tan x , t gk¡ i zfr y kse f=kdks.kfer h; Qy u tan–1x dk eku   2 , 2  esekur sgS
,
 1 ; fn x  0  

(iii) f3(x) = [sin(loge(x +2))] gS
,t gk¡ t  R dsfy , , [t], t l sde ; k cj kcj egÙke i w
. kkZ
a
d dksn' kkZ
r k gS
A
 2 1
x sin   ; fn x  0
(iv) f4(x) =  x
 0 ; fn x  0

lw
ph- I lw
ph- II
P. Qy u f1 gS& 1. x = 0 i j l r r ~ughgS &
Q. Qy u f2 gS
& 2. x = 0 i j l r r ~gSy sfdu x = 0 i j vody uh; ughgS
A
R. Qy u f3 gS
& 3. x = 0 i j vody uh; gSr Fkk bl dk vody t
x = 0 ij l r r ~ughgS &
S. Qy u f4 gS
& 4. x = 0 i j v od y uh; gS r Fkk bl d k v od y t
x = 0 ij l r r ~gS
&

l ghfodYi gS
&
(A) P  2, Q  3; R  1; S  4
(A) P  4, Q  1; R  2; S  3
(A) P  4, Q  2; R  1; S  3
(A) P  2, Q  1; R  4; S  3

Sol. (D)
2
(i) f(x)  sin 1  e x

1
f1' (x)  cos 1  e x .
2

2 1e  x2
0  e  x2
.  2x  
at x=0 f1' (x) does not exist
So. P  2

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99, 8003899588
JEE (MAIN + ADVANCED) Examination (2018) (Page # 53)

 sin x
 ,x  0
f2 (x)   tan1 x
(ii)
0 x=0

sinx x
lim 1
x0 x tan1 x
 f2  x  does not continuous at x = 0
so Q  1
(iii) f3  x   sin n  x  2    0
1< x + 2 < e / 2

 0< n x  2  
2

 0<sin( n(x  2))  1


 f3  x   0
So R  4
 2 1
x sin , x0
(iv)  f4  x    x
 0 , x=0

So S  3

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