Răspuns:
3/4
Explicație pas cu pas:
cos(5π/6)=cos(π- π/6)=cos(π/6).
sin(π/3)·cos(5π/6)=sin(π/3)·cos(π/6)=((√3)/2)·((√3)/2)=((√3)/2)²=3/4
Intradevar sin(π/3)=sin(π/2 - π/6)=cos(π/6)
Deci expresia poate fi sin(π/3)·cos(π/6)=cos(π/6)·cos(π/6)=(cos(π/6))²=((√3)/2)²=3/4
