函数y=k/x(k≠0)叫作反比例函数,它的图象是双曲线.它的性质有:当k>0时,图象在一、三象限,且在每个象限内y随x增大而减小.当k<0时,图象在二、四象限,且在每个象限内y随x增大而增大.下面,我们运用这些基本知识来讨论几个问题:一、利用几何性质例1如图1,平行四边形ABCD的顶点是A、B的坐标分别是A(-1,0),B(0,-2),顶点C、D在双曲线y=k/x(k≠0)上,边AD交y轴于点E,且四边形BCDE的 The function y = k / x (k ≠ 0) is called an inverse function, and its image is a hyperbola. It has the following properties: when k> 0, the image is in the first and third quadrants and in each quadrant y As k increases, the image is in quadrants two and four, and y increases with x in each quadrant. Here are some basic questions that we will discuss using these basics: First, the use of geometric properties Example 1 Figure 1, the parallelogram ABCD vertex is A, B coordinates are A (-1,0), B (0, -2), vertices C, D hyperbolic in the y = k / x (k ≠ 0), the side AD intersects the y-axis at point E, and the quadrilateral BCDE