函数y=sin(x+π/4)sin(π/4-x)的最小值
问题描述:
函数y=sin(x+π/4)sin(π/4-x)的最小值
答
y=sin(x+π/4)sin(π/4-x)
=sin(x+π/4)cos(π//2-π/4+x)
=sin(x+π/4)cos(x+π/4)
=1/2sin(2x+π/2)
=1/2cos2x
最小值1/2