π/12ln2
π/8ln2
π/4ln2
π/32ln2
I=∫₁⁄₂₀log(1+2x)/(1+4x²)dxLet 2x=tanθ2dx=sec²θdθI=∫π/₄₀(1/2)log(1+tanθ)dθI=(1/2)∫π/₄₀log(1+tan(π/4−θ))dθ=(1/2)∫π/₄₀log(2/(1+tanθ))dθ=(1/2)∫π/₄₀(log2−log(1+tanθ))dθ(3/2)I=(1/2)∫π/₄₀log2dθI=π/12log2