f(x)=2sinxcosx -cos(2x-6分之派)
发布网友
发布时间：2024-10-23 02:45
共2个回答
热心网友
时间：2024-11-04 11:54
=sin2x-sin(2x+π/3)
=2cos[(2x+2x+π/3)/2]sin[(2x-2x-π/3)/2]
=cos(2x+π/6)
（1）f(x)的最小正周期为π
（2）2x∈[0,4π/3]
2x+π/6∈[π/6,3π/2]
所以当x=0时，f(x)取得最大值根号3/2
热心网友
时间：2024-11-04 11:54
f(π/4)=√2sin(2*π/4+π/4)=√2*√2/2=1
0<α<π
π/4<α+π/4<5π/4
f(α/2)=√2sin(α+π/4)=√2/2
sin(α+π/4)=1/2
α+π/4=5π/6
α=7π/12=π/3+π/4
sinα=sinπ/3cosπ/4+cosπ/3sinπ/4=(√6+√2)/4
请参考
