如题所述
若f(θ╱2+∏╱12)=6/5,θ∈(0,∏/2)求sin2θ
f(θ/2+π/12)=6/5,θ∈(0,π/2)求sin2θf(θ/2+π/12)=2sin[2(θ/2+π/12)+π/3]=2sin(θ+π/2)=2cosθ=6/5∴cosθ=3/5∵θ∈(0,π/2)∴sinθ=4/5sin2θ=2sinθcosθ=2×3/5×4/5=24/25