题目
题型:不详难度:来源:
A.0 | B.1 | C.2 | D.-1 |
答案
∴圆心到直线的距离等于半径,
∴1=
|a+1| | ||
|
∴|a+1|=
a2+1 |
∴a=0
故选A.
核心考点
举一反三
A.5x-12y+17=0 |
B.5x-12y+17=0或5x+12y+17=0 |
C.x=-1或5x+12y+17=0 |
D.x=-1或5x-12y+17=0 |
x2 |
16 |
y2 |
4 |
(1)求切线l的方程;
(2)求弦AB的长.
A.0 | B.1 | C.2 | D.-1 |
|a+1| | ||
|
a2+1 |
A.5x-12y+17=0 |
B.5x-12y+17=0或5x+12y+17=0 |
C.x=-1或5x+12y+17=0 |
D.x=-1或5x-12y+17=0 |
x2 |
16 |
y2 |
4 |