根據(jù)函數(shù)在點(diǎn)(x0,y0)處的導(dǎo)數(shù)定義,以Δx代表x1-x0,即lim(Δx→0)(y1-y0)/(x1-x0)可知,式子(y1-y0)/(x1-x0)的意義即過(guò)定點(diǎn)(x0,y0)的割線斜率,當(dāng)Δx→0時(shí),動(dòng)點(diǎn)(x1,y1)趨于定點(diǎn)(x0,y0),即割線趨于和切線重合,極限即為切線,其斜率即為切線斜率.如下圖所示: 向左轉(zhuǎn)|向右轉(zhuǎn) |
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來(lái)自: agrobest > 《高中數(shù)學(xué)》