Question

求函数y=（2分之1）x+cosx(-2π

Answer 1

y!=1/2-sinx,y!=0 ,x=π/6 ,x=5π/6

x=-7π/6 ,x=-11π/6

(-2π,-11π/6) y!0

(-7π/6,π/6) y!0

(7π/6,2π) ,y!