题目
题型:成都模拟难度:来源:
x2 |
16 |
y2 |
9 |
A.16 | B.8 | C.6 | D.4 |
答案
x2 |
16 |
y2 |
9 |
∴其长轴长2a=8,
又其左、右焦点分别为F1、F2,P为椭圆上一点,
∴|PF1|+|PF2|=2a=2×4=8.
故选B.
核心考点
举一反三
x2 |
a2 |
y2 |
b2 |
A.y=±
| B.y=±
| C.x=±
| D.x=±
|
x2 |
m2 |
y2 |
n2 |
x2 |
16 |
y2 |
12 |
x2 |
16 |
y2 |
9 |
A.16 | B.8 | C.6 | D.4 |
x2 |
16 |
y2 |
9 |
x2 |
a2 |
y2 |
b2 |
A.y=±
| B.y=±
| C.x=±
| D.x=±
|
x2 |
m2 |
y2 |
n2 |
x2 |
16 |
y2 |
12 |