右=(tanπ/5+b/a)/(1-b/a*tanπ/5)右=(sinπ/5/cosπ/5+b/a)/(1-b/a*sinπ/5/cosπ/5) 分子、分母同乘a*cosπ/5右=(asinπ/5+bcosπ/5)/(a*cosπ/5-bsinπ/5)左=(asinπ/5+bcosπ/5)/(a*cosπ/5-bsinπ/5)所以：左=...