已知函数f(x)=2sinxsin(x+π/3) 求函数f(x)的最大值
已知函数f(x)=2sinxsin(x+π/3) 求函数f(x)的最大值
日期:2019-07-22 21:32:30 人气:1
f(x)=2sinxsin(x+π/3)
=2sinx(sinxcosπ/3+cosxsinπ/3)
=2sinx(1/2*sinx+√3/2*cosx)
=sin²x+√3sinxcosx
=(1-cos2x)/2
+
√3*sin2x/2
=1/2-cos2x
/
2
+
√3*sin2x/2
=1/2-cosπ/3cos2x+sinπ/3sin2x
=1/