“方程的根与函数的零点”:(2)

DIV.MyFav_1194939600536 P.MsoNormal{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 LI.MsoNormal{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 DIV.MsoNormal{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 P.MsoBodyTextIndent{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 7.8pt 0cm 0pt; TEXT-INDENT: 21pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 LI.MsoBodyTextIndent{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 7.8pt 0cm 0pt; TEXT-INDENT: 21pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 DIV.MsoBodyTextIndent{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 7.8pt 0cm 0pt; TEXT-INDENT: 21pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 P.MsoPlainText{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: 宋体; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 LI.MsoPlainText{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: 宋体; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 DIV.MsoPlainText{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: 宋体; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 P{FONT-SIZE: 12pt; MARGIN-LEFT: 0cm; MARGIN-RIGHT: 0cm; FONT-FAMILY: 宋体}DIV.MyFav_1194939600536 P.MTDisplayEquation{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt 18pt; TEXT-INDENT: -18pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 LI.MTDisplayEquation{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt 18pt; TEXT-INDENT: -18pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 DIV.MTDisplayEquation{TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt 18pt; TEXT-INDENT: -18pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify}DIV.MyFav_1194939600536 DIV.Section1{page: Section1}DIV.MyFav_1194939600536 OL{MARGIN-BOTTOM: 0cm}DIV.MyFav_1194939600536 UL{MARGIN-BOTTOM: 0cm} 一．内容和内容解析 本节内容有函数零点概念、函数零点与相应方程根的关系、函数零点存在性定理． 函数零点是研究当函数的值为零时，相应的自变量的取值，反映在函数图象上，也就是函数图象与轴的交点横坐标． 由于函数的值为零亦即，其本身已是方程的形式，因而函数的零点必然与方程有着不可分割的联系，事实上，若方程有解，则函数存在零点，且方程的根就是相应函数的零点，也是函数图象与轴的交点横坐标．顺理成章的，方程的求解问题，可以转化为求函数零点的问题．这是函数与方程关系认识的第一步． 零点存在性定理，是函数在某区间上存在零点的充分不必要条件．如果函数在区间[a,b]上的图象是一条连续不断的曲线，并且满足f(a)·f(b)