jee-main 2019 Q77

jee-main · India · session1_12jan_shift2 Not Maths
If $A = \left[ \begin{array} { c c c } 1 & \sin \theta & 1 \\ - \sin \theta & 1 & \sin \theta \\ - 1 & - \sin \theta & 1 \end{array} \right]$, then for all $\theta \in \left( \frac { 3 \pi } { 4 } , \frac { 5 \pi } { 4 } \right) , \operatorname { det } ( A )$ lies in the interval :
(1) $\left( 1 , \frac { 5 } { 2 } \right]$
(2) $\left[ \frac { 5 } { 2 } , 4 \right)$
(3) $\left( \frac { 3 } { 2 } , 3 \right]$
(4) $\left( 0 , \frac { 3 } { 2 } \right]$
If $A = \left[ \begin{array} { c c c } 1 & \sin \theta & 1 \\ - \sin \theta & 1 & \sin \theta \\ - 1 & - \sin \theta & 1 \end{array} \right]$, then for all $\theta \in \left( \frac { 3 \pi } { 4 } , \frac { 5 \pi } { 4 } \right) , \operatorname { det } ( A )$ lies in the interval :\\
(1) $\left( 1 , \frac { 5 } { 2 } \right]$\\
(2) $\left[ \frac { 5 } { 2 } , 4 \right)$\\
(3) $\left( \frac { 3 } { 2 } , 3 \right]$\\
(4) $\left( 0 , \frac { 3 } { 2 } \right]$