问题
填空题
将函数y=sinx-
|
答案
y=sinx-
cosx=2sin(x-3
)π 3
假设沿x轴向右平移a个单位得到y=2sin(x-a-
)的图象关于y轴对称π 3
∴2sin(x-a-
)=2sin(-x-a-π 3
)π 3
sinxcos(a+
)-cosxsin(a+π 3
)=-sinxcos(a+π 3
)-cosxsin(a+π 3
)π 3
∴sinxcos(a+
)=0∴cos(a+π 3
)=0∴a+π 3
=π 3
+kππ 2
∴α=
+kπ∴a的最小值为π 6 π 6
故答案为:π 6