(3)f(θ)的值域.
解(1)观察可知BC与地面所成的角θ的取值范围为0,π/2.
(2)如图,连接BD,则∠DBC=π/6,过D作地面的垂线,垂足为E,在Rt△BED中,∠DBE=θ+π/6,DB=2,
∴f(θ)=2sinθ+π/60≤θ≤π/2.
(3)f(θ)=2sinθ+π/60≤θ≤π/2,π/6≤θ+π/6≤2π/3,∴1/2≤sinθ+π/6≤1,即f(θ)的值域为[1,2].