a=(cos2x,sinx),b=(1,2sinx-1),x∈(π/2,π),若a*b=2/5,则tan(x+π/4)=?
问题描述:
a=(cos2x,sinx),b=(1,2sinx-1),x∈(π/2,π),若a*b=2/5,则tan(x+π/4)=?
答
a=(cos2x,sinx),b=(1,2sinx-1),x∈(π/2,π),若a*b=2/5,则tan(x+π/4)=?