f(x)=sin2x/3+cos2x/3的图像中相邻的两条对称轴间距离为
问题描述:
f(x)=sin2x/3+cos2x/3的图像中相邻的两条对称轴间距离为
A3π B4π/3 C3π/2 D7π/6
答
f(x)=√2(2x/3+π/4)
T=2π/(2/3)=3π
所以最短距离=T/2
选Cf(x)=√2(2x/3+π/4)这怎么化来的?sinx+cosx =√2(√2/2*sinx+√2/2cosx) =√2(sinxcosπ/4+cosxsinπ/4) =√2sin(x+π/4)=√2(sinxcosπ/4+cosxsinπ/4)这一步又是怎么来的?sorry,反应有点慢cosπ/4 sinπ/4=√2sin(x+π/4)这是怎么从上一步化来的?详细点嘛和角公式 别追问了