100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
(IIT)(JEE)(Engineering) $2.99   Add to cart

Exam (elaborations)

(IIT)(JEE)(Engineering)

 6 views  0 purchase
  • Course
  • Institution

Paper on JEE exam which was held on 29th of feb 2024

Preview 3 out of 24  pages

  • July 30, 2024
  • 24
  • 2023/2024
  • Exam (elaborations)
  • Questions & answers
avatar-seller
FINAL JEE–MAIN EXAMINATION – JANUARY, 2024
(Held On Monday 29th January, 2024) TIME : 3 : 00 PM to 6 : 00 PM

MATHEMATICS TEST PAPER WITH SOLUTION
SECTION-A 3. Let P(3, 2, 3), Q (4, 6, 2) and R (7, 3, 2) be the
2 1 2  1 2 0  vertices of PQR. Then, the angle QPR is
1. Let A = 6 2 11 and P =  5 0 2  . The sum
    7
 3 3 2  7 1 5  (1) (2) cos1  
6  18 
of the prime factors of P 1AP  2I is equal to  1 
(3) cos1   (4)
(1) 26 (2) 27 (3) 66 (4) 23  18  3
Ans. (1) Ans. (4)
1 1 1
Sol. P AP  2I  P AP  2P P Sol. P(3, 2, 3)

= P 1 (A  2I)P 

= P 1 A  2I P Q(4, 6, 2) R(7, 3, 2)
Direction ratio of PR = (4, 1, -1)
= |A-2I|
01 2 Direction ratio of PQ = (1, 4, -1)
 6 0 11 = 69 4  4 1
Now, cos  
3 3 0 18. 18

So, Prime factor of 69 is 3 & 23 

So, sum = 26 3
2. Number of ways of arranging 8 identical books 4. If the mean and variance of five observations are
into 4 identical shelves where any number of 24 194
shelves may remain empty is equal to and respectively and the mean of first
5 25
(1) 18 (2) 16 (3) 12 (4) 15
7
Ans. (4) four observations is , then the variance of the
2
Sol. 3 Shelf empty : (8, 0, 0, 0)  1way
first four observations in equal to
(7,1,0,0) 
4 77 5 105
(6, 2,0,0)  (1) (2) (3) (4)
2 shelf empty :  4ways 5 12 4 4
(5,3,0,0) 
 Ans. (3)
(4, 4,0,0) 
24 2 194
(6,1,1,0) (3,3, 2,0)  Sol. X ; 
5 25
1 shelf empty : (5, 2,1,0) (4, 2, 2,0)   5ways
Let first four observation be x1, x2, x3, x4
(4,3,1,0) 
x1  x 2  x 3  x 4  x 5 24
(1, 2,3, 2) (5,1,1,1)  Here,  ......(1)
5 5
(2, 2, 2, 2) 
0 Shelf empty :   5ways x1  x 2  x 3  x 4 7
(3,3,1,1)  Also, 
 4 2
(4, 2,1,1) 
 x1  x 2  x 3  x 4  14
Total = 15 ways

, Now from eqn -1 6. Let r and  respectively be the modulus and
x5 = 10 amplitude of the complex number
194  5 
Now, 2  z  2  i  2 tan  , then (r, ) is equal to
25  8 
x12  x 22  x 32  x 24  x 52 576 194
   3 3 
5 25 25 (1)  2sec , 
 8 8 
 x12  x22  x32  x42  54
 3 5 
Now, variance of first 4 observations (2)  2sec , 
 8 8 
2
4
 4 
 x i2   xi   5 3 
(3)  2sec , 
Var = i 1
  i 1   8 8 
4  4 
   11 11 
  (4)  2sec ,
 8 8 
54 49 5
  =
4 4 4 Ans. (1)
2
 5 
5. The function f(x) = 2x  3(x) 3 ,x  , has Sol. z = 2  i  2 tan  = x + iy (let)
 8 
(1) exactly one point of local minima and no
y
point of local maxima r= x 2  y 2 &   tan 1
x
(2) exactly one point of local maxima and no
2
point of local minima  5 
r = (2)2   2 tan 
 8 
(3) exactly one point of local maxima and
exactly one point of local minima 5  3 
= 2sec  2sec    
(4) exactly two points of local maxima and 8  8 
exactly one point of local minima 3
Ans. (3) = 2 sec
8
2
Sol. f (x)  2x  3(x) 3  5 
 2 tan
&   tan 1  8 
1 
f '(x)  2  2x 3  2 
 
 1 
= 2 1  1    5  
  = tan 1  tan     
 x3    8 

 13  3
 x 1 =
= 2 1  8
 x3 
  7. The sum of the solutions x  of the equation
+ – +
3cos2x  cos3 2x
–1 0 = x3 – x2 + 6 is
cos6 x  sin 6 x
M m
So, maxima (M) at x = -1 & minima(m) at x = 0 (1) 0 (2) 1
(3) –1 (4) 3

, Ans. (3) Ans. (1)
3cos2x  cos3 2x Sol. logea, logeb, logec are in A.P.
Sol. = x3 – x2 + 6  b2 = ac …..(i)
cos x  sin x
6 6

Also
cos2x (3  cos2 2x)
 = x 3 – x2 + 6  a   2b   3c 
cos2x (1  sin 2 x cos2 x) loge   ,loge   ,loge   are in A.P.
 2b   3c   a 
4(3  cos2 2x)
 = x3 – x2 + 6 2
(4  sin 2 2x)  2b  a 3c
 3c   2b  a
 
4(3  cos2 2x)
 = x3 – x2 + 6 b 3
(3  cos2 2x) 
c 2
x3 – x2 + 2 = 0  (x + 1)(x2 – 2x + 2) = 0
2b
so, sum of real solutions = –1 Putting in eq. (i) b2 = a ×
3
8. Let OA  a,OB  12a  4b and OC  b, where O
a 3
is the origin. If S is the parallelogram with adjacent 
b 2
sides OA and OC, then a :b:c=9:6:4
area of the quadrilateral OABC 10. If
is equal to ___
area of S 3 3
sin 2 x  cos 2 x
(1) 6 (2) 10  sin 3 x cos3 x sin(x  )
dx  A cos  tan x  sin   B cos   sin  cot x  C,

(3) 7 (4) 8 where C is the integration constant, then AB is
Ans. (4) equal to
B (1) 4 cosec(2) (2) 4sec 
A
Sol. (3) 2sec  (4) 8cosec(2)
12a + 4b
a Ans. (4)
3 3
sin 2 x  cos 2 x
Sol.  sin 3 x cos3 x sin(x  )
dx

O C 3 3
b
sin 2 x  cos 2 x
Area of parallelogram, S  a  b I=  sin 3 x cos3 x (sin x cos   cos x sin )
dx

Area of quadrilateral =Area(OAB)+Area (OBC) 3 3

= sin 2 x cos 2 x
dx =
=
1
2
a  (12a  4b)  b  (12a  4b)   3
sin x cos x tan x cos   sin 
2 2
dx   3
sin x cos x cos   cot xsin 
2 2



sec2 x cosec2 x
= 8 (a  b)  tan x cos   sin 
dx  
cos   cot xsin 
dx

8 (a  b) I = I1 + I2 …… {Let}
Ratio = =8
(a  b) For I1, let tan x cos  – sin  = t2
2t dt
9. If loge a, loge b, loge c are in an A.P. and loge a – sec 2 x dx 
cos 
loge2b, loge2b – loge3c, loge3c – loge a are also in
For I2 , let cos   cot xsin   z2
an A.P, then a : b : c is equal to
2z dz
(1) 9 : 6 : 4 (2) 16 : 4 : 1 cosec 2 x dx 
sin 
(3) 25 : 10 : 4 (4) 6 : 3 : 2

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller clover1. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for $2.99. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

75759 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy study notes for 14 years now

Start selling
$2.99
  • (0)
  Add to cart