f(x)=sin(2x+6/π)+sin(2x-6/π)
=√3/2sin2x+1/2cos2x+√3/2sin2x-1/2cos2x
=√3sin2x
T=2π/2=π
2x在[2kπ+π/2,2kπ+3π/2]是单调递减
x在[kπ+π/4,kπ+3π/4]是单调递减
2)
f(x)=sin(2x+6/π)+sin(2x-6/π)
=√3/2sin2x+1/2cos2x+√3/2sin2x-1/2cos2x
=√3sin2x
T=2π/2=π
2x在[2kπ+π/2,2kπ+3π/2]是单调递减
x在[kπ+π/4,kπ+3π/4]是单调递减
2)