令a=√6sinx
则b²=6-6sin²x=6cos²x
b=√6cosx
a+b=√6(sinx+cosx)
=√6[√2(√2/2*sinx+√2/2cosx)]
=2√3(sinxcosπ/4+cosxsinπ/4)
=2√3sin(x+π/4)
所以最小值=-2√3
令a=√6sinx
则b²=6-6sin²x=6cos²x
b=√6cosx
a+b=√6(sinx+cosx)
=√6[√2(√2/2*sinx+√2/2cosx)]
=2√3(sinxcosπ/4+cosxsinπ/4)
=2√3sin(x+π/4)
所以最小值=-2√3