tan(α+π/6)=(tanα+tan(π/6))/(1-tanαtan(π/6))=(tanα+1/√3)/(1-tanα/√3)=(1+√3tanα)/(√3-tanα)=2解得tanα=(2√3-1)/(√3+2)=5√3-8tan²α=64+75-80√3=139-80√3sin2α=2tanα/(1+tan²α)=...