&=π/4
f（x）=sin（3x+π/4）,m=π/12
cosπ/4cos&-sin3π/4sin&=cosπ/4cos&-sinπ/4sin&=cos(π/4+&)=0,因为&绝对值＜π/2 ,所以π/4+&大于-π/4小于3π/4,所以π/4+&=π/2,&=π/4
函数f（x）的图像的相邻两条对称轴之间的距离等于π/3,2π/w=2*π/3,w=3,所以f（x）=sin（3x+π/4）,由函数图象知对称轴为kπ/3+π/4,固向左平移π/12个单位长度图象变为偶函数