Question

函数Y=2sin(兀/3－x)－cos(兀/6＋x) 的最小值

Answer 1

=2sin(兀/3－x)－cos(兀/6＋x)
=2cos(兀/2-(兀/3－x))－cos(兀/6＋x)
=2cos(兀/6＋x) -cos(兀/6＋x)
=cos(兀/6＋x)
最小值为-1

Answer 2

y=2sin（π/3-x）-cos（π/6+x）
=2sin(π/3-x)-sin[π/2-(π/6+x)]
=2sin(π/3-x)-sin(π/3-x)
=sin(π/3-x)
=-sin(x-π/3)

T=2π/1=2π
最大值是1，最小值是-1