题目内容
椭圆
+
=1上的点到直线x+2y-
=0的最大距离是( )
| x2 |
| 16 |
| y2 |
| 4 |
| 2 |
| A.3 | B.
| C.2
| D.
|
设椭圆
+
=1上的点P(4cosθ,2sinθ)
则点P到直线x+2y-
=0的距离
d=
=
dmax=
=
;
故选D.
| x2 |
| 16 |
| y2 |
| 4 |
则点P到直线x+2y-
| 2 |
d=
|4cosθ+4sinθ-
| ||
|
|4
| ||||||
|
|-4
| ||||
|
| 10 |
故选D.
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