在二次函数的图象和性质的教学过程中,有关二次函数y=a(x+h)2+k的平移问题,同学们普遍感到困难.其关键在于h、k的符号与平移方向之间的关系难以记清,解题时也容易出现错误.实际上,由于抛物线的移动是整体平移,利用顶点的平移就可反映出抛物线的平移情况.例1抛物线y=2x2+4x-1是由抛物线y=2x2怎样平移得到的? In the teaching of quadratic function image and character, students generally find it difficult to solve the translation problem of the quadratic function y = a (x + h) 2 + k. The key lies in the sign and translation direction of h, k In fact, since the movement of the parabola is a global translation, the translation of the vertices can reflect the translation of the parabola Example 1 Parabola y = 2x2 + 4x-1 Is the parabola y = 2x2 how to get the translation?