JEE MAIN - Mathematics (2022 - 25th June Evening Shift)
1
Let $$A = \{ x \in R:|x + 1| < 2\} $$ and $$B = \{ x \in R:|x - 1| \ge 2\} $$. Then which one of the following statements is NOT true?
Answer
(B)
$$B - A = R - ( - 3,1)$$
2
Let a, b $$\in$$ R be such that the equation $$a{x^2} - 2bx + 15 = 0$$ has a repeated root $$\alpha$$. If $$\alpha$$ and $$\beta$$ are the roots of the equation $${x^2} - 2bx + 21 = 0$$, then $${\alpha ^2} + {\beta ^2}$$ is equal to :
Answer
(B)
58
3
Let z1 and z2 be two complex numbers such that $${\overline z _1} = i{\overline z _2}$$ and $$\arg \left( {{{{z_1}} \over {{{\overline z }_2}}}} \right) = \pi $$. Then :
Answer
(C)
$$\arg {z_1} = {\pi \over 4}$$
4
The system of equations
$$ - kx + 3y - 14z = 25$$
$$ - 15x + 4y - kz = 3$$
$$ - 4x + y + 3z = 4$$
is consistent for all k in the set
Answer
(D)
R $$-$$ {$$-$$11, 11}
5
$$\mathop {\lim }\limits_{x \to {\pi \over 2}} \left( {{{\tan }^2}x\left( {{{(2{{\sin }^2}x + 3\sin x + 4)}^{{1 \over 2}}} - {{({{\sin }^2}x + 6\sin x + 2)}^{{1 \over 2}}}} \right)} \right)$$ is equal to
Answer
(A)
$${1 \over {12}}$$
6
The area of the region enclosed between the parabolas y2 = 2x $$-$$ 1 and y2 = 4x $$-$$ 3 is
Answer
(A)
$${1 \over {3}}$$
7
The coefficient of x101 in the expression $${(5 + x)^{500}} + x{(5 + x)^{499}} + {x^2}{(5 + x)^{498}} + \,\,.....\,\, + \,\,{x^{500}}$$, x > 0, is
Answer
(A)
501C101 (5)399
8
Water is being filled at the rate of 1 cm3 / sec in a right circular conical vessel (vertex downwards) of height 35 cm and diameter 14 cm. When the height of the water level is 10 cm, the rate (in cm2 / sec) at which the wet conical surface area of the vessel increases is
Answer
(C)
$${{\sqrt {26} } \over 5}$$
9
If $${b_n} = \int_0^{{\pi \over 2}} {{{{{\cos }^2}nx} \over {\sin x}}dx,\,n \in N} $$, then
Answer
(D)
$${1 \over {{b_3} - {b_2}}},{1 \over {{b_4} - {b_3}}},{1 \over {{b_5} - {b_4}}}$$ are in an A.P. with common difference $$-$$2
10
If $$y = y(x)$$ is the solution of the differential equation
$$2{x^2}{{dy} \over {dx}} - 2xy + 3{y^2} = 0$$ such that $$y(e) = {e \over 3}$$, then y(1) is equal to :
Answer
(B)
$${2 \over 3}$$
11
The value of 2sin (12$$^\circ$$) $$-$$ sin (72$$^\circ$$) is :
Answer
(D)
$${{\sqrt 3 (1 - \sqrt 5 )} \over 4}$$
12
A biased die is marked with numbers 2, 4, 8, 16, 32, 32 on its faces and the probability of getting a face with mark n is $${1 \over n}$$. If the die is thrown thrice, then the probability, that the sum of the numbers obtained is 48, is :
Answer
(D)
$${{13} \over {{2^{12}}}}$$
13
The value of $${\tan ^{ - 1}}\left( {{{\cos \left( {{{15\pi } \over 4}} \right) - 1} \over {\sin \left( {{\pi \over 4}} \right)}}} \right)$$ is equal to :
Answer
(B)
$$ - {\pi \over 8}$$
14
The line y = x + 1 meets the ellipse $${{{x^2}} \over 4} + {{{y^2}} \over 2} = 1$$ at two points P and Q. If r is the radius of the circle with PQ as diameter then (3r)2 is equal to :
Answer
(A)
20
15
Let $$A = \left( {\matrix{
2 & { - 2} \cr
1 & { - 1} \cr
} } \right)$$ and $$B = \left( {\matrix{
{ - 1} & 2 \cr
{ - 1} & 2 \cr
} } \right)$$. Then the number of elements in the set {(n, m) : n, m $$\in$$ {1, 2, .........., 10} and nAn + mBm = I} is ____________.
Answer
1
16
Let $$f(x) = \left[ {2{x^2} + 1} \right]$$ and $$g(x) = \left\{ {\matrix{
{2x - 3,} & {x < 0} \cr
{2x + 3,} & {x \ge 0} \cr
} } \right.$$, where [t] is the greatest integer $$\le$$ t. Then, in the open interval ($$-$$1, 1), the number of points where fog is discontinuous is equal to ______________.
Answer
62
17
The value of b > 3 for which $$12\int\limits_3^b {{1 \over {({x^2} - 1)({x^2} - 4)}}dx = {{\log }_e}\left( {{{49} \over {40}}} \right)} $$, is equal to ___________.
Answer
6
18
If the sum of the co-efficient of all the positive even powers of x in the binomial expansion of $${\left( {2{x^3} + {3 \over x}} \right)^{10}}$$ is $${5^{10}} - \beta \,.\,{3^9}$$, then $$\beta$$ is equal to ____________.
Answer
83
19
If the mean deviation about the mean of the numbers 1, 2, 3, .........., n, where n is odd, is $${{5(n + 1)} \over n}$$, then n is equal to ______________.
Answer
21
20
Let $$\overrightarrow b = \widehat i + \widehat j + \lambda \widehat k$$, $$\lambda$$ $$\in$$ R. If $$\overrightarrow a $$ is a vector such that $$\overrightarrow a \times \overrightarrow b = 13\widehat i - \widehat j - 4\widehat k$$ and $$\overrightarrow a \,.\,\overrightarrow b + 21 = 0$$, then $$\left( {\overrightarrow b - \overrightarrow a } \right).\,\left( {\widehat k - \widehat j} \right) + \left( {\overrightarrow b + \overrightarrow a } \right).\,\left( {\widehat i - \widehat k} \right)$$ is equal to _____________.
Answer
14
21
The total number of three-digit numbers, with one digit repeated exactly two times, is ______________.
Answer
243
22
Let $$f(x) = |(x - 1)({x^2} - 2x - 3)| + x - 3,\,x \in R$$. If m and M are respectively the number of points of local minimum and local maximum of f in the interval (0, 4), then m + M is equal to ____________.
Answer
3
23
Let l1 be the line in xy-plane with x and y intercepts $${1 \over 8}$$ and $${1 \over {4\sqrt 2 }}$$ respectively, and l2 be the line in zx-plane with x and z intercepts $$ - {1 \over 8}$$ and $$ - {1 \over {6\sqrt 3 }}$$ respectively. If d is the shortest distance between the line l1 and l2, then d$$-$$2 is equal to _______________.