求函数y=2sin(2π/3+4x)+cos(π/6+4x)单调区间

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求函数y=2sin(2π/3+4x)+cos(π/6+4x)单调区间求函数y=2sin(2π/3+4x)+cos(π/6+4x)单调区间求函数y=2sin(2π/3+4x)+cos(π/6+4x)单调

求函数y=2sin(2π/3+4x)+cos(π/6+4x)单调区间
求函数y=2sin(2π/3+4x)+cos(π/6+4x)单调区间

求函数y=2sin(2π/3+4x)+cos(π/6+4x)单调区间
y=2sin(2π/3+4x)+cos(π/6+4x)
=2*√3/2*cos4x-2*1/2*sin4x+√3/2*cos4x-1/2*sin4x
=√3cos4x-sin4x+√3/2*cos4x-1/2*sin4x
=3√3/2*cos4x-3/2*sin4x
=3(√3/2*cos4x-1/2*sin4x)
=3cos(4x+π/6)
单调增区域为:
π+2kπ≤4x-π/6≤2π+2kπ,k为整数
7π/6+2kπ≤4x≤13π/6+2kπ,k为整数
7π/24+kπ/2≤x≤13π/24+kπ/2,k为整数
则单调增区间为[7π/24+kπ/2,13π/24+kπ/2],k为整数
同理:单调减区间为:[1π/24+kπ/2,7π/24+kπ/2],k为整数