论文部分内容阅读
二次函数y=ax2+bx+c(a,b,c是常数,a≠0)的系数a,b,c的符号和它的图像之间有着相辅相成的关系.由二次函数的图像位置可以得到a,b,c(或者含有的a,b,c的代数式)的符号;反之,由a,b,c(或者含有的a,b,c的代数式)的符号也可以确定图像的位置.这是一种由形到数、由数到形的转换,是数形结合思想的很好的诠释.也是一种等价、同一的关系,
The coefficients a, b, c of the quadratic function y = ax2 + bx + c (a, b, c are constants, a ≠ 0) have a complementarity relationship with the sign of the image. The symbols of a, b, c (or algebraic formulas containing a, b, c) can be obtained. Conversely, the symbols of a, b, c (or algebraic formulas of a, b, c) This is a kind of conversion from form to number, from number to form, and is a good interpretation of the idea of combining numbers and forms. It is also an equivalent and same relationship,