Question

(1/2)已知函数f(x)=x-acosx,x属于(负2分之派,2分之派), 1,当a=-2时,求函数f(x)的极大值

Answer 1

(1)f(x)=x+2cosx

f'(X)=1-2sinx

f'(x)=0,sinx=1/2

x属于(负2分之派,2分之派),

x=π/6

(-π/2,π/6)f'(x)>0,f(x)递增

(π/6,π/2),f'(x)