问题
填空题
函数y=
|
答案
∵函数y=
的定义域为Rkx2-6kx+9
∴kx2-6kx+9≥0，x∈R恒成立
①当k=0时，9≥0成立
②当k＞0时，△=（-6k）2-4×k×9≤0
得0＜k≤1
由①②得0≤k≤1
故答案是[0，1]
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函数y=
|
∵函数y=
的定义域为Rkx2-6kx+9
∴kx2-6kx+9≥0，x∈R恒成立
①当k=0时，9≥0成立
②当k＞0时，△=（-6k）2-4×k×9≤0
得0＜k≤1
由①②得0≤k≤1
故答案是[0，1]
| 阅读理解。 | |
| |
| 1. Mrs.Yang wants _______ for her daughter. | |
| A. a babysitter B. a good graduate C. an English tutor D. a math tutor | |
| 2. If you are the tutor, you must teach the daughter for _______ on Saturday. | |
| A. a day B. two hours C. three hours D. a whole afternoon | |
| 3. What is not a part of the job? | |
| A. Cooking for the kids. B. Working at the kid's house. C. Being good with the kid. D. Telling English stories to the kid. | |
| 4. If you want to be the tutor, you need to _______. ①be beautiful ②have three years' teaching experience ③have time on weekends ④be a woman teacher | |
| A. ①② B. ②③ C. ②③④ D. ①②③ | |
| 5. Which is NOT true? | |
| A. The tutor must teach the kid on weekends. B. The kid is good at English. C. The tutor can speak English. D. The tutor can get $360, if she teaches the kid for two weekends. |