1/5单选题
难度：
1.
已知关于x的一元二次方程
有实数根，则实数a的取值范围是（ ）
| A | a≤1 |
| B | a<1 |
| C | a≤-1 |
| D | a≥1 |
- 提示1：
- PHA+5pa556iL5pyJ5a6e5pWw5qC577yM5YiZ4paz4omlMO+8jOW7uueri+WFs+S6jmHnmoTkuI3nrYnlvI/vvIzmsYLlh7ph55qE5Y+W5YC86IyD5Zu0LjwvcD4=
正确答案：QQ==
PHA+6Kej77ya55Sx6aKY5oSP55+l77yM4pazPTQtNGHiiaUwPGJyPuKItGHiiaQxLjxicj7mlYXpgIlBLjwvcD4=
2/5单选题
难度：
2.
已知关于x的一元二次方程(a－1)x2－2x+1=0有两个不相等的实数根,则a的取值范围是( )
| A | a<2 |
| B | a>2 |
| C | a<2且a≠1 |
| D | a<－2 |
- 提示1：
- PHA+5Yik5Yir5byP5aSn5LqOMDwvcD4=
正确答案：Qw==
PHA+6Kej4oi15pa556iL5pyJ5Lik5Liq5LiN55u4562J55qE5a6e5pWw5qC577yMPGJyPuKItOKWsz3vvIgtMu+8iTxzdXA+Mjwvc3VwPi00w5fvvIhhLTHvvIk9NC00YSs0PTgtNGHvvJ4w77yMPGJyPuino+W+l2HvvJwy77yMPGJyPuWPiOKIteaWueeoi++8iGEtMe+8iXg8c3VwPjI8L3N1cD4tMngrMT0w5Li65LiA5YWD5LqM5qyh5pa556iL77yMPGJyPuKItGEtMeKJoDDvvIw8YnI+5Y2zYeKJoDHvvIw8YnI+5pWF6YCJQy48L3A+
3/5单选题
难度：
3.
关于x的一元二次方程mx2-x+1=0有实根，则m的取值范围是( )
| A | m≤ |
| B | m≤ |
| C | m＞0 |
| D | m≥ |
- 提示1：
- PHA+55Sx5LqOeOeahOS4gOWFg+S6jOasoeaWueeoi214PHN1cD4yPC9zdXA+LXgrMT0w5pyJ5a6e5qC577yM6YKj5LmI5LqM5qyh6aG557O75pWw5LiN562J5LqOMO+8jOW5tuS4lOWFtuWIpOWIq+W8j+KWs+aYr+mdnui0n+aVsO+8jOeUseatpOWPr+S7peW7uueri+WFs+S6jm3nmoTkuI3nrYnlvI/nu4TvvIzop6PkuI3nrYnlvI/nu4TljbPlj6/msYLlh7pt55qE5Y+W5YC86IyD5Zu0LjwvcD4=
正确答案：Qg==
PHA+6Kej77ya4oi15YWz5LqOeOeahOS4gOWFg+S6jOasoeaWueeoi214PHN1cD4yPC9zdXA+LXgrMT0w5pyJ5a6e5qC577yMPGJyPuKItG3iiaAw77yM5bm25LiU4pazPWI8c3VwPjI8L3N1cD4tNGFjPTEtNG3iiaUw77yMPGJyPuKItG3iiaQ8aW1nIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvNDAvMUUvckJBQ0ZGUFY4SFRoTHE0M0FBQUJLVmdncnVRNDg1LnBuZyIgZGF0YS1ja2Utc2F2ZWQtc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC80MC8xRS9yQkFDRkZQVjhIVGhMcTQzQUFBQktWZ2dydVE0ODUucG5nIiBoZWlnaHQ9IjQyIiB3aWR0aD0iNiI+5LiUbeKJoDAuPGJyPumAiUI8L3A+
4/5单选题
难度：
4.
已知关于x的一元二次方程（k-1）x2-2x+1=0有两个不相等的实数根，则k的取值范围是( )
| A | k＜-2 |
| B | k＜2 |
| C | k＞2 |
| D | k＜2且k≠1 |
- 提示1：
- PHA+5qC55o2u5pa556iL5pyJ5Lik5Liq5LiN55u4562J55qE5a6e5pWw5qC577yM5b6X5Yiw5qC555qE5Yik5Yir5byP55qE5YC85aSn5LqOMOWIl+WHuuWFs+S6jmvnmoTkuI3nrYnlvI/vvIzmsYLlh7rkuI3nrYnlvI/nmoTop6Ppm4bljbPlj6/lvpfliLBr55qE6IyD5Zu0LjwvcD4=
正确答案：RA==
PHA+6Kej77ya5qC55o2u6aKY5oSP5b6X77ya4pazPWI8c3VwPjI8L3N1cD4tNGFjPTQtNO+8iGstMe+8iT04LTRr77yeMO+8jOS4lGstMeKJoDDvvIw8YnI+6Kej5b6X77yaa++8nDLvvIzkuJRr4omgMS48YnI+5pWF6YCJRDwvcD4=
5/5单选题
难度：
5.
若a，b，c为正数，已知关于x的一元二次方程ax2+bx+c=0有两个相等的实根，则方程（a+1）x2+（b+2）x+c+1=0的根的情况是( )
| A | 没有实根 |
| B | 有两个相等的实根 |
| C | 有两个不等的实根 |
| D | 根的情况不确定 |
- 提示1：
- PHA+5YWI5qC55o2u5YWz5LqOeOeahOS4gOWFg+S6jOasoeaWueeoi2F4PHN1cD4yPC9zdXA+K2J4K2M9MOacieS4pOS4quebuOetieeahOWunuagueehruWumuWHuuKWsz1iPHN1cD4yPC9zdXA+LTRhYz0w77yMPC9wPg==
- 提示2：
- PHA+5YaN5rGC5pa556iL77yIYSsx77yJeDxzdXA+Mjwvc3VwPivvvIhiKzLvvIl4K2MrMT0w55qE5qC555qE5Yik5Yir5byP77yM5bm25bCG4pazPWI8c3VwPjI8L3N1cD4tNGFjPTDku6PlhaXlhbbkuK3ov5vooYzljJbnroA8L3A+
- 提示3：
- PHA+54S25ZCO5qC55o2u5a6D5LiOMOeahOWkp+Wwj+adpeWIpOaWreivpeaWueeoi+eahOagueeahOaDheWGtS48L3A+
正确答案：RA==
PHA+6Kej77ya4oi15YWz5LqOeOeahOS4gOWFg+S6jOasoeaWueeoi2F4PHN1cD4yPC9zdXA+K2J4K2M9MOacieS4pOS4quebuOetieeahOWunuague+8jDxicj7iiLTilrM9YjxzdXA+Mjwvc3VwPi00YWM9MO+8jDxicj7liJnmlrnnqIvvvIhhKzHvvIl4PHN1cD4yPC9zdXA+K++8iGIrMu+8iXgrYysxPTDnmoTmoLnnmoTliKTliKvlvI/kuLrvvJo8YnI+4pazPe+8iGIrMu+8iTxzdXA+Mjwvc3VwPi0077yIYSsx77yJ77yIYysx77yJ77yMPGJyPj1iPHN1cD4yPC9zdXA+KzRiLTRhYy00YS00Yz1iPHN1cD4yPC9zdXA+LTRhYys077yIYi1hLWPvvIk8YnI+PTTvvIhiLWEtY++8iTxicj7iiLU077yIYi1hLWPvvInnmoTlpKflsI/msqHms5Xnoa7lrprvvIw8YnI+4oi04pazPe+8iGIrMu+8iTxzdXA+Mjwvc3VwPi0077yIYSsx77yJ77yIYysx77yJ55qE56ym5Y+35rKh5rOV56Gu5a6a77yMPGJyPuKItOaWueeoi++8iGErMe+8iXg8c3VwPjI8L3N1cD4r77yIYisy77yJeCtjKzE9MOeahOagueeahOaDheWGteaXoOazleehruWumu+8mzxicj7mlYXpgIlELjwvcD4=