1
JEE Main 2020 (Online) 4th September Morning Slot
+4
-1
If $$A = \left[ {\matrix{ {\cos \theta } & {i\sin \theta } \cr {i\sin \theta } & {\cos \theta } \cr } } \right]$$, $$\left( {\theta = {\pi \over {24}}} \right)$$

and $${A^5} = \left[ {\matrix{ a & b \cr c & d \cr } } \right]$$, where $$i = \sqrt { - 1}$$ then which one of the following is not true?
A
$$a$$2 - $$c$$2 = 1
B
$$0 \le {a^2} + {b^2} \le 1$$
C
$$a$$2 - $$d$$2 = 0
D
$${a^2} - {b^2} = {1 \over 2}$$
2
JEE Main 2020 (Online) 3rd September Evening Slot
+4
-1
Out of Syllabus
Let A be a 3 $$\times$$ 3 matrix such that
adj A = $$\left[ {\matrix{ 2 & { - 1} & 1 \cr { - 1} & 0 & 2 \cr 1 & { - 2} & { - 1} \cr } } \right]$$ and B = adj(adj A).

If |A| = $$\lambda$$ and |(B-1)T| = $$\mu$$ , then the ordered pair,
(|$$\lambda$$|, $$\mu$$) is equal to :
A
(3, 81)
B
$$\left( {9,{1 \over 9}} \right)$$
C
$$\left( {3,{1 \over {81}}} \right)$$
D
$$\left( {9,{1 \over {81}}} \right)$$
3
JEE Main 2020 (Online) 3rd September Morning Slot
+4
-1
If $$\Delta$$ = $$\left| {\matrix{ {x - 2} & {2x - 3} & {3x - 4} \cr {2x - 3} & {3x - 4} & {4x - 5} \cr {3x - 5} & {5x - 8} & {10x - 17} \cr } } \right|$$ =

Ax3 + Bx2 + Cx + D, then B + C is equal to :
A
-1
B
-3
C
9
D
1
4
JEE Main 2020 (Online) 2nd September Evening Slot
+4
-1
Let a, b, c $$\in$$ R be all non-zero and satisfy
a3 + b3 + c3 = 2. If the matrix

A = $$\left( {\matrix{ a & b & c \cr b & c & a \cr c & a & b \cr } } \right)$$

satisfies ATA = I, then a value of abc can be :
A
3
B
$${1 \over 3}$$
C
-$${1 \over 3}$$
D
$${2 \over 3}$$
EXAM MAP
Medical
NEET