$f(x)=\frac{cos(x)}{2+sin(x)}$

Solution: Zeroes: $x=\frac{}{2}+2k,\frac{3}{2}+2k$

Local Maxes: $(\frac{11}{6}+2k,\frac{\sqrt[\phantom{2}]{3}}{3})$

Local Mins: $(\frac{7}{6}+2k,-\frac{\sqrt[\phantom{2}]{3}}{3})(\frac{3}{2}+2k,0)$

Inflection points: $($pi$/2+2($pi$)($k$),0),(3$pi$/2+2($pi$)($k$),0)$

can you help to show how they got the solution?