1
JEE Main 2020 (Online) 2nd September Evening Slot
+4
-1
If the equation cos4 $$\theta$$ + sin4 $$\theta$$ + $$\lambda$$ = 0 has real solutions for $$\theta$$, then $$\lambda$$ lies in the interval :
A
$$\left[ { - {3 \over 2}, - {5 \over 4}} \right]$$
B
$$\left( { - {1 \over 2}, - {1 \over 4}} \right]$$
C
$$\left( { - {5 \over 4}, - 1} \right]$$
D
$$\left[ { - 1, - {1 \over 2}} \right]$$
2
JEE Main 2020 (Online) 9th January Evening Slot
+4
-1
If $$x = \sum\limits_{n = 0}^\infty {{{\left( { - 1} \right)}^n}{{\tan }^{2n}}\theta }$$ and $$y = \sum\limits_{n = 0}^\infty {{{\cos }^{2n}}\theta }$$

for 0 < $$\theta$$ < $${\pi \over 4}$$, then :
A
x(1 + y) = 1
B
y(1 – x) = 1
C
y(1 + x) = 1
D
x(1 – y) = 1
3
JEE Main 2020 (Online) 9th January Morning Slot
+4
-1
The value of
$${\cos ^3}\left( {{\pi \over 8}} \right)$$$${\cos}\left( {{3\pi \over 8}} \right)$$+$${\sin ^3}\left( {{\pi \over 8}} \right)$$$${\sin}\left( {{3\pi \over 8}} \right)$$
is :
A
$${1 \over {\sqrt 2 }}$$
B
$${1 \over 2}$$
C
$${1 \over 4}$$
D
$${1 \over 2{\sqrt 2 }}$$
4
JEE Main 2019 (Online) 12th April Morning Slot
+4
-1
The equation y = sinx sin (x + 2) – sin2 (x + 1) represents a straight line lying in :
A
B
C
D