JEE (Main)-2023 : Phase-2 (06-04-2023)-Morning MATHEMATICS Sol. SECTION - A Multiple Choice Questions: This section contains 20 multiple choice questions. Each question has 4 choices (1), (2), (3) and (4), out of which ONLY ONE is correct. Choose the correct answer: 1. Tn = 5 + The number of ways to distribute 20 chocolates among three students such that each student will get atleast one chocolate is (1) 22 C2 (2) 19 (3) 19 C3 (4) 22 Tn = 5 + 6 ( n − 1) + ( n − 1)( n − 2 ) Tn = n 2 + 3n + 1 C2 C3 Tn = Answer (2) x 1, y 1, z 1 where x1 = x + 1 y1 = y + 1 z1 = z + 1 Number of ways = = 4. 17 +3 −1 C3 −1 19 C2 +n Mean of first 15 numbers is 12 and variance is 14. Mean of next 15 numbers is 14 and variance is a. If variance of all 30 numbers is 13, then a is equal to (1) 12 (2) 14 (3) 10 (4) 3 Sol. 2 = (1) 14 (2) 15 (3) 15 (4) 14 C7 C6 C8 13 = C8 xi2 2 – (x ) n (14 + 144) 15 + (a + 196) 15 – (13)2 30 a = 10 Answer (3) 1 Cr ( x 4 )15 −r − 3 x 5. r 15 If the image of point P(1, 2, 3) about the plane 2x – y + 3y = 2 is Q, then the area of triangle PQR, where coordinates of R is (4, 10, 12) Cr x 60 − 4r − 3r ( − 1)r 15 Now, 60 – 7r = 18 (1) 1531 2 (2) 1675 2 (3) 2443 2 (4) 1784 2 r=6 coefficient of x18 is 15 C6 Sum of first 20 turns of the series 5, 11, 19, 29, 41, …… is (1) 3130 (2) 3520 (3) 2790 (4) 1880 Answer (2) 2 Answer (3) 15 4 1 x − 3 x 3. 3 ( n )( n + 1) = 2870 + 630 + 20 = 3520 The coefficient of x18 in the expansion of = 6 + 20 21 41 3 20 21 + + 20 6 2 S20 = x1 + y1 + z1 = 17 Sol. Tr +1 = ( n )( n + 1)( 2n + 1) n = 20 Sol. x + y + z = 20 2. n −1 (12 + ( n − 2) 2) 2 Answer (1) - 12 - JEE (Main)-2023 : Phase-2 (06-04-2023)-Morning Sol. Image formula x −1 y − 2 z − 3 2−2+9−2 = = = −2 2 −1 3 14 x = –1 = 1 5log2 − 6 + 3 9 = 1 5 ( log2 ) − 3 9 2 y=3 18 f ( x ) dx = 10log2 − 6 z=0 1 7. The sum of roots of x 2 − 8 x + 15 − 2 x + 7 = 0 is (1) 11 + 3 (2) 11 − 3 (3) 9 + 3 PQ = −2i + j − 3k (4) 9 − 3 Answer (3) PR = 3i + 8 j + 9k Sol. x 2 − 8 x + 15 − 2 x + 7 = 0 1 Area = PQ PR 2 6. ( x − 3)( x − 5) − 2 x + 7 = 0 1 = 33i + 9 j − 19k 2 Let x 3 or x 5, then 1531 = 2 x2 – 10x + 22 = 0 x2 – 8x + 15 – 2x + 7 = 0 2 x= 5 3 but x (–, 3] [5, ) 3 1 x =5 + 3 1 1 If 5f ( x ) + 4f = + 3 , then 18 f ( x ) dx is x x (1) 10log2 + 6 (2) 10log2 − 6 Now, (3) 5log2 + 6 (4) 5log2 − 6 x (3, 5), then Answer (2) –x2 + 8x – 15 – 2x + 7 = 0 1 1 5 5f ( x ) + 4f = + 3 x x 1 Sol. x→ x 1 4 5f + 4f ( x ) = x + 3 x x2 – 6x + 8 = 0 ...(i) x = 2, 4 x=4 Sum of roots = 9 + 3 ...(ii) 8. (1) (P R) Q 5 9f ( x ) = + 15 − 4 x − 12 x 5 9f ( x ) = − 4 x + 3 x 2 f ( x ) dx = 1 1 9 (P Q) (R Q) is equivalent to (2) (P R) Q (3) (Q R) (P R) (4) (R P) (Q R) Answer (1) Sol. (P Q) (R Q) = (~P Q) (~R Q) 2 5 x − 4 x + 3 dx 1 = (~P ~R) Q = ~ (PR) Q 2 1 = 5log x − 2 x 2 + 3 x 1 9 = (PR) Q - 13 - JEE (Main)-2023 : Phase-2 (06-04-2023)-Morning 9. Let a = 2i + 3 ˆj + 4kˆ, b = iˆ − 2 jˆ − 2kˆ, c = −iˆ + 4 jˆ + 3kˆ x 2 ( x sec 2 x + tan x ) ( x tan x + 1)2 and d is a vector perpendicular to both b and c (1) 720 (2) 640 (3) 680 (4) 760 11. From the top of 30 m tower AB the angle of depression to another tower’s QP base and top is 60º and 30º respectively. Another point C lies on tower AB such that CQ is parallel to BP (where B and P are the base of towers). Then the area of BCQP is Answer (1) Sol. b c = 2iˆ − jˆ + 2kˆ d = (2iˆ − jˆ + 2kˆ ) (1) 600 a · d = 18 (3) 600 ( ) 3 −1 ( 300 ( (2) 600 (4) ) 3 − 1) 3 +1 Answer (1) =2 Sol. | a d |2 = | a |2 · | d |2 −(a · d )2 −x2 + 2log | x sin x + cos x | + c x tan x + 1 = and a · d = 18 , then | a d |2 is dx = 720 10. The integration x 2 ( x sec 2 x + tan x ) ( x tan x + 1)2 dx is (1) x + log | x sin x + cos x | + c x tan x + 1 (2) x − log | x sin x + cos x | + c x tan x + 1 (3) −x + 2log | x sin x + cos x | + c x tan x + 1 (4) x2 + 2log | x sin x + cos x | + c x tan x + 1 tan60º = 2 BP = 10 3 tan15º = x 2 · I ( ( x sec 2 x + tan x ) ( x tan x + 1) 2 ( Now area = BP × QP ( = 10 3 60 − 20 3 I Let xsinx + cosx = t = 600 ( ) 3 −1 dy 12. If 2y x + 3 x y = 20 , then is equal to dx at ( 2,2 ) (xcosx + sinx – sinx) dx = dt (1) dt = 2log t + c t = 2log | x sin x + cos x | + c ) = 600 3 − 600 x dx x tan x + 1 x cos x = 2 dx x sin x + cos x = 2 ) = 60 − 20 3 − x2 2x + dx ( x tan x + 1) x tan x + 1 I = 2 ) QP = 30 − 10 3 2 − 3 dx II = AC 10 3 AC = 10 3 2 − 3 Answer (3) Sol. 30 BP − ( 8 + 12ln2 ) (12 + 8ln2 ) (3) 8ln + 12 Answer (2) - 14 - (2) − ( 8ln2 + 12 ) ( 8 + 12ln2 ) (4) 8 + 12ln2 JEE (Main)-2023 : Phase-2 (06-04-2023)-Morning Sol. 2y x + 3 x y = 20 Sol. …(i) Let u = yx lnu = xlny 1 dy x dy = + ln y u dx y dx Let v = xy lnv = y lnx 1 dy y dy = + ln x v dx x dx Now (i) differentiate w.r.t. x Equation of OG : dy dv 2 +3 =0 dx dx Equation of BE : y dy x dy 2y x + ln y + 3 x y + ln x = 0 y dx x dx Put x = 2, y = 2 dy dy 8 + ln 2 + 12 1 + ln 2 = 0 dx dx 13. Number of words with (or) without meaning using all the letters of the word ASSASSINATION such that all the vowels come together is (1) 38004 (2) 38042 (3) 50400 (4) 60200 15. 16. 17. Answer (3) Sol. SSSSNTN 18. A AIAIO 19. 7 20. Number of required words SECTION - B 8! 6! = 50400 4! 2! 3! 2! 14. If a cuboid has its sides along axes with lengths 3, 4 and 5, find the shortest distance between body diagonal and the side not containing the vertices of body diagonal. (1) (2) (3) (4) 20 41 12 5 Numerical Value Type Questions: This section contains 10 questions. In Section B, attempt any five questions out of 10. The answer to each question is a NUMERICAL VALUE. For each question, enter the correct numerical value (in decimal notation, truncated/rounded-off to the second decimal place; e.g., 06.25, 07.00, –00.33, –00.30, 30.27, –27.30) using the mouse and the on-screen virtual numeric keypad in the place designated to enter the answer. 21. Let a1, a2, a3,… an are in arithmetic progression having common difference as ‘d’. The value of 15 d n → n lim 34 18 5 Answer (2) 1 1 1 + + ... a + a a + a a + a 1 2 2 3 n − 1 n is _______ Answer (1) - 15 - JEE (Main)-2023 : Phase-2 (06-04-2023)-Morning d n → n Sol. lim d n → n = lim = lim n → n −4 1 1 1 + + ... a + a a2 + a3 an –1 + an 2 1 a 2 – a1 a – a2 a – an –1 + 3 + ... n a2 – a1 a3 – a2 an – an –1 d 1 – n d ( an – a1 4 1 −1 3 4 C4 2 4 T = 6 Sol. 5 = n −4 4 T5 ' −1 1 n 4 4 C4 3 2 n ) 1 = 24 1 a1 + ( n – 1) d – a1 n → d n = lim 1 a a d = lim 1 + d – – 1 n d n → d n n− 8 4 n −4−4 ( 6) n −8 1 = 4 2 1 . 3 4 n −4−4 1 = ( 6) 2 n–8=2 =1 n = 10 22. Matrix A is 2 × 2 matrix and A2 = I, no elements of 24. If 2nC3 : nC3 = 10, then the matrix is zero, let sum of diagonal elements is a and det(A) = b, then the value of 3a2 + b2 is n 2 + 3n n 2 − 3n + 4 is equal to Answer (02) Answer (1) u v u Sol. w x w 1 = (6)2 Sol. v x u2 + vw = 1 uv + vx = 0 u = –v wu + wx = 0 u = –x u + x = 0 = a 3! ( n − 3 ) ! 2n ! = 10 3! ( 2n − 3 )! n! ( 2n )( 2n − 1)( 2n − 2 ) = 10 n ( n − 1)( n − 2 ) 4 ( 2n − 1) = 10n − 20 2n = 16 n = 8 wv + x2 = 1 |A2| = |I| det(A) = 1 n 2 + 3n 2 n − 3n + 4 = 64 + 24 88 = = 02 64 − 24 + 4 44 b = 1 25. The number of points of non-differentiability of the function f(x) = [4 + 13sinx] in (0, 2) is ____. 3a2 + b2 = 3 × 0 + 1 = 1 Answer (50) Sol. Number of points of non-differentiability 4 + [13 sinx] is 4 × 12 + 2 = 50 (by graph) 23. Ratio of terms of 5th term from beginning and 5th n term from end is 1 4 1 . The value 6 : 1 in 2 + 1 34 26. 27. 28. of n is _______. 29. Answer (10) 30. ❑ ❑ - 16 - ❑ for