12.已知函数f(x)=3sin(ωx+φ)−cos(ωx+φ)(ω>0,∣φ∣<π)f(x)=\sqrt{3}\sin (\omega x+\varphi )-\cos (\omega x+\varphi )(\omega >0,\vert \varphi \vert <\pi )f(x)=3sin(ωx+φ)−cos(ωx+φ)(ω>0,∣φ∣<π),则"函数f(x)f(x)f(x)是偶函数"是"φ=−π3\varphi =-\frac{\pi }{3}φ=−3π"的((( )))