JEE MAIN - Mathematics (2020 - 3rd September Morning Slot)
1
For the frequency distribution :
Variate (x) : x1 x2 x3
.... x15 Frequency (f) : f1
f2
f3
...... f15 where 0 < x1
< x2
< x3
< ... < x15 = 10 and
$$\sum\limits_{i = 1}^{15} {{f_i}} $$ > 0, the standard deviation cannot be :
Let [t] denote the greatest integer
$$ \le $$ t. If for some
$$\lambda $$ $$ \in $$ R - {1, 0}, $$\mathop {\lim }\limits_{x \to 0} \left| {{{1 - x + \left| x \right|} \over {\lambda - x + \left[ x \right]}}} \right|$$ = L, then L is
equal to :
If y2 + loge (cos2x) = y, $$x \in \left( { - {\pi \over 2},{\pi \over 2}} \right)$$, then :
Answer
(A)
|y''(0)| = 2
11
$$\int\limits_{ - \pi }^\pi {\left| {\pi - \left| x \right|} \right|dx} $$ is equal to :
Answer
(A)
$${\pi ^2}$$
12
Consider the two sets :
A = {m $$ \in $$ R : both the roots of x2
– (m + 1)x + m + 4 = 0 are real}
and B = [–3, 5).
Which of the following is not true?
Answer
(D)
A - B = ($$ - $$$$ \propto $$, $$ - $$3) $$ \cup $$ (5, $$ \propto $$)
13
Let P be a point on the parabola, y2
= 12x and
N be the foot of the perpendicular drawn from
P on the axis of the parabola. A line is now
drawn through the mid-point M of PN, parallel
to its axis which meets the parabola at Q. If the
y-intercept of the line NQ is $${4 \over 3}$$,
then :
Answer
(D)
MQ = $${1 \over 4}$$
14
The area (in sq. units) of the region
{ (x, y) : 0 $$ \le $$ y $$ \le $$ x2 + 1, 0 $$ \le $$ y $$ \le $$ x + 1,
$${1 \over 2}$$ $$ \le $$ x $$ \le $$ 2 } is :
Answer
(B)
$${{79} \over {24}}$$
15
A hyperbola having the transverse axis of
length
$$\sqrt 2 $$ has the same foci as that of the ellipse
3x2 + 4y2 = 12, then this hyperbola does not
pass through which of the following points?
If the first term of an A.P. is 3 and the sum of
its first 25 terms is equal to the sum of its next
15 terms, then the common difference of this
A.P. is :
Answer
(D)
$${1 \over 6}$$
17
The lines
$$\overrightarrow r = \left( {\widehat i - \widehat j} \right) + l\left( {2\widehat i + \widehat k} \right)$$ and
$$\overrightarrow r = \left( {2\widehat i - \widehat j} \right) + m\left( {\widehat i + \widehat j + \widehat k} \right)$$
Answer
(A)
do not intersect for any values of $$l$$ and m
18
A dice is thrown two times and the sum of the
scores appearing on the die is observed to be
a multiple of 4. Then the conditional probability
that the score 4 has appeared atleast once is :
Answer
(B)
$${1 \over 9}$$
19
If $${\left( {{{1 + i} \over {1 - i}}} \right)^{{m \over 2}}} = {\left( {{{1 + i} \over {1 - i}}} \right)^{{n \over 3}}} = 1$$, (m, n
$$ \in $$ N) then the
greatest common divisor of the least values of
m and n is _______ .