题目

如图，已知双曲线y1=﹣与两直线y2=﹣x，y3=﹣8x，若无论x取何值，y总取y1，y2，y3中的最小值，则y的最大值为．                                                                                                                                                                                                                                    二次函数y=x2+px+q部分对应值可列表如下：x00.511.11.21.3y-15-8.75-2-0.590.842.29则一元二次方程x2+px+q=0正根的范围是 ．