题目
题型:不详难度:来源:
MO |
MF |
答案
p |
2 |
设M(m,n),则n2=2pm,m>0,设M 到准线x=-
p |
2 |
则
|MO| |
|MF| |
|MO| |
d |
| ||
m+
|
| ||
m+
|
|
1+
|
令 pm-
p2 |
4 |
p2 |
4 |
t |
p |
p |
4 |
∴
|MO| |
|MF| |
1+
|
1+
|
1+
|
2
| ||
3 |
3 |
4 |
故
|MO| |
|MF| |
2
| ||
3 |
故答案为
2
| ||
3 |
核心考点
举一反三
MO |
MF |
p |
2 |
p |
2 |
|MO| |
|MF| |
|MO| |
d |
| ||
m+
|
| ||
m+
|
|
1+
|
p2 |
4 |
p2 |
4 |
t |
p |
p |
4 |
|MO| |
|MF| |
1+
|
1+
|
1+
|
2
| ||
3 |
3 |
4 |
|MO| |
|MF| |
2
| ||
3 |
2
| ||
3 |