$\left| {\begin{array}{*{20}{c}} {1 + {{\sin }^2}{\rm{\theta }}}&{{{\sin }^2}{\rm{\theta }}}&{{{\sin }^2}{\rm{\theta }}}\\ {{{\cos }^2}{\rm{\theta }}}&{1 + {{\cos }^2}{\rm{\theta }}}&{{{\cos }^2}{\rm{\theta }}}\\ {4\sin 4{\rm{\theta }}}&{4\sin 4{\rm{\theta }}}&{1 + 4\sin 4{\rm{\theta }}} \end{array}} \right| = 0,$ then $\sin 4\theta $ equals to

JEE MATHEMATICS MCQ: MATRICES

1 Easy

1 of 1

Application +4 | -1

\left| {\begin{array}{cccccccccccccccccccc} {1 + {{\sin }^2}\mathrm{\theta }}&{{{\sin }^2}\mathrm{\theta }}&{{{\sin }^2}\mathrm{\theta }}\\ {{{\cos }^2}\mathrm{\theta }}&{1 + {{\cos }^2}\mathrm{\theta }}&{{{\cos }^2}\mathrm{\theta }}\\ {4\sin 4\mathrm{\theta }}&{4\sin 4\mathrm{\theta }}&{1 + 4\sin 4\mathrm{\theta }} \end{array}} \right| = 0,

then

\sin 4\theta

equals to

View answer and explanation

Correct option: C

\frac{{ - 1}}{2}

Option C (

\frac{{ - 1}}{2}

) is correct because after applying row and column operations, the equation simplifies to

\sin 4\theta = - \frac{1}{2}

Practice All Chapter MCQs →

\left|\begin{array}{ccc}a & b-c & b+c \\ c+a & b & c-a \\ a-b & a+b & c\end{array}\right|=0

a, b, c

a x+b y+c=0

{x_2} - {x_3} = 1,\; - {x_1} + 2{x_3} = - 2,\;{x_1} - 2,\;{x_1} - 2{x_2} = 3

2x + 3y + 1 = 0,3x + y - 2 = 0

ax + 2y - b = 0

\left|\begin{array}{ccc}1 & \left(\alpha^{2 x}-\alpha^{-2 x}\right)^2 & \left(\alpha^{2 x}+\alpha^{-2 x}\right)^2 \\ 1 & \left(\beta^{2 x}-\beta^{-2 x}\right)^2 & \left(\beta^{2 x}+\beta^{-2 x}\right)^2 \\ 1 & \left(\gamma^{2 x}-\gamma^{-2 x}\right)^2 & \left(\gamma^{2 x}+\gamma^{-2 x}\right)^2\end{array}\right|

\omega

\left| {\begin{array}{cccccccccccccccccccc} 1&\omega &{{\omega ^2}}\\ \omega &{{\omega ^2}}&1\\ {{\omega ^2}}&1&\omega \end{array}} \right|

A

2 \times 2

A(\operatorname{adj} A)=\left[\begin{array}{cc}10 & 0 \\ 0 & 10\end{array}\right]

|A|