利用变式思想进行学习与训练,是学活相关知识、建立知识间关系网的重要途径和方法.以下以一道常州市中考数学题为例,探究求一次函数解析式的变式训练,希望对同学们的学习有所帮助.[原题]已知一次函数y=kx+b的图像经过点A(0,-2)、B(1,0),则b=______,k=______.[解析]由已知条件,得b=-2,k+b=0,解得:k=2,b=-2,此题是想让同学们会用待定系数法求一次函数解析式.[变式1]已知一次函数y=kx+b,当x=0时 The use of variant ideas for learning and training is an important way to learn relevant knowledge and establish a network of knowledge. Here is an example of a Changzhou middle school entrance examination mathematics problem. The students’ learning helps. [Original title] Once the image of a function y=kx+b is known to pass point A(0,-2), B(1,0), then b=______, k=______.[ Analytical] from the known conditions, get b = -2, k + b = 0, solution: k = 2, b = -2, this question is for students to use undetermined coefficient method for a function analytical formula. [ Variant 1] Known first-order function y = kx + b, when x = 0