斜率者,線之正切也,亦線之高除以進,記曰 m {\displaystyle m} ,有 註︰蓋當今數學之事,誠難僅以文述,而無符號,故凡數學之文,咸有漢字、拉丁字相易之事,以合文言、數學,則無論文理之人,皆可明之也。 m = tan α = y 2 − y 1 x 2 − x 1 = y 1 − y 2 x 1 − x 2 {\displaystyle m=\tan \alpha ={\frac {y_{2}-y_{1}}{x_{2}-x_{1}}}={\frac {y_{1}-y_{2}}{x_{1}-x_{2}}}} Remove adsLoading related searches...Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads