If $A=\left[\begin{array}{ccc}\cos \theta & \sin \theta & 0 \\ -\sin \theta & \cos \theta & 0 \\ 0 & 0 & 1\end{array}\right]$, where $A_{21}, A_{22}, A_{23}$ are cofactors of $a_{21}, a_{22}, a_{23}$ respectively, then the value of $\mathrm{a}_{21} \mathrm{~A}_{21}+\mathrm{a}_{22} \mathrm{~A}_{22}+\mathrm{a}_{23} \mathrm{~A}_{23}=$

In a triangle $A B C$, with usual notations, if $\frac{b+c}{11}=\frac{c+a}{12}=\frac{a+b}{13}$ Then $\cos \mathrm{A}: \cos \mathrm{B}: \cos \mathrm{C}$ is

The formula for the physical quantity is $\mathrm{P}=\frac{\mathrm{x}^3 \mathrm{y}}{\mathrm{z}^2}$ and the percentage error in the determination of physical quantities $\mathrm{x}, \mathrm{y}, \mathrm{z}$ are $0.6 \%, 3 \%$ and $1.3 \%$ respectively. The percentage error in the measurement of P is

Let ' $W$ ' joule be the work done to move an electric charge ' $q$ ' coulomb from a place $A$, where potential is -5 volt to another place $B$ where potential is ' $V$ ' volt. The value of ' $V$ ' is