Let f(x)=4sinx2sinx+4cosx\displaystyle {f{{\left({x}\right)}}}=\frac{{{4}{\sin{{x}}}}}{{{2}{\sin{{x}}}+{4}{\cos{{x}}}}}.

Then f(x)=\displaystyle {f}'{\left({x}\right)}=  

The equation of the tangent line to y=f(x)\displaystyle {y}={f{{\left({x}\right)}}} at a=π3\displaystyle {a}=\frac{\pi}{{3}} can be written in the form y=mx+b\displaystyle {y}={m}{x}+{b} where
m=\displaystyle {m}=   and
b=\displaystyle {b}=