问题
单项选择题
方程x3+x-2=0根的情况为()。
A.没有实根
B.有一个实根
C.有两个实根
D.有3个实根
答案
参考答案:B
解析:
显然有f(1)=0,从而x-1是x3+x-2的一个因式,则有x3+x-2=(x-1)(x2+x+2),所以只有一个实根x=1,选(B).
方程x3+x-2=0根的情况为()。
A.没有实根
B.有一个实根
C.有两个实根
D.有3个实根
参考答案:B
解析:
显然有f(1)=0,从而x-1是x3+x-2的一个因式,则有x3+x-2=(x-1)(x2+x+2),所以只有一个实根x=1,选(B).
从下列方框中选适当的词填空,注意其形式变化。 | |
2. What are the fine ____ you should find in a great person? 3. After a short rest, Jack ____ to draw the picture. 4. Since I was better ____, I got a job working in an office. 5. The doctor ____ him to eat more fruit and take more exercise. 6. He has been able to tell us more about ____ volcanoes (火山) than any man alive. 7. I hope people all over the world will lead a ____ life. 8. Could you be so kind as to tell me the exact ____ of the supermarket? |