$\begin{aligned}
& d E=3 \alpha^2 d \alpha e^{-\beta t}+\alpha^3 e^{-\beta t}(-\beta) d t \
& \frac{d E}{E}=\frac{3 d \alpha}{\alpha}+(-\beta) d t \
& \frac{\Delta E}{E}=\frac{3 \Delta \alpha}{\alpha}+\beta \Delta t
\end{aligned}(%)\Delta t=1.6 % \times 5=8 %%\left(\frac{3 \Delta \alpha}{\alpha}\right)=3 \times 1.2 %=3.6 %Puttingvaluesweget\Rightarrow 3.6+8 \times 0.3=6 %$