If $\cos 4\mathrm{x}={\mathrm{a}}_0+{\mathrm{a}}_1{\cos }^2\mathrm{x}+{\mathrm{a}}_2{\cos }^4\mathrm{x}$ s true for all values of $\mathrm{x}\in \mathrm{R}$ then the value of $5{\mathrm{a}}_0+{\mathrm{a}}_1+{\mathrm{a}}_2$ is

$\begin{array}{l}\cos 4\mathrm{x}=2{\cos }^{2}2\mathrm{x}-1\\ =2{\left(2{\cos }^2\mathrm{x}-1\right)}^2-1\\ =2\left(4{\cos }^4\mathrm{x}+1-4{\cos }^2\mathrm{x}\right)-1\\ =8{\cos }^4\mathrm{x}-8{\cos }^2\mathrm{x}+1\\ \therefore {\mathrm{a}}_0=1,{\mathrm{a}}_1=-8,{\mathrm{a}}_2=8\\ \therefore 5{\mathrm{a}}_0+{\mathrm{a}}_1+{\mathrm{a}}_2=5\end{array}$