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双曲线x2a2-y2b2=1(a>0,b>0)的渐近线与抛物线y2=-4x的准线交于P、Q两点,O为原点,若△OPQ的面积等于3,则双曲线的离心率为()A.22B.10C.3D.37

题目详情
x2
a2
-
y2
b2
=1(a>0,b>0)的渐近线与抛物线y2=-4x的准线交于P、Q两点,O为原点,若△OPQ的面积等于3,则双曲线的离心率为(  )
A. 2
2

B.
10

C. 3
D.
37
x2
a2
x2x2x2x22a2a2a2a22
y2
b2
=1(a>0,b>0)的渐近线与抛物线y2=-4x的准线交于P、Q两点,O为原点,若△OPQ的面积等于3,则双曲线的离心率为(  )
A. 2
2

B.
10

C. 3
D.
37
y2
b2
y2y2y2y22b2b2b2b222
2

B.
10

C. 3
D.
37
2
2
2
10

C. 3
D.
37
10
10
10

37
37
37
37
▼优质解答
答案和解析
∵双曲线
x2
a2
-
y2
b2
=1(a>0,b>0),
∴双曲线的渐近线方程是y=±
b
a
x,
又∵抛物线y2=-4x的准线方程为x=1,
∵双曲线
x2
a2
-
y2
b2
=1(a>0,b>0)的两条渐近线与抛物线y2=-4x的准线分别交于P,Q两点,
∴P,Q两点的纵坐标分别是y=
b
a
和y=-
b
a

∵△OPQ的面积等于3,∴
1
2
×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
x2
a2
x2x2x22a2a2a22-
y2
b2
=1(a>0,b>0),
∴双曲线的渐近线方程是y=±
b
a
x,
又∵抛物线y2=-4x的准线方程为x=1,
∵双曲线
x2
a2
-
y2
b2
=1(a>0,b>0)的两条渐近线与抛物线y2=-4x的准线分别交于P,Q两点,
∴P,Q两点的纵坐标分别是y=
b
a
和y=-
b
a

∵△OPQ的面积等于3,∴
1
2
×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
y2
b2
y2y2y22b2b2b22=1(a>0,b>0),
∴双曲线的渐近线方程是y=±
b
a
x,
又∵抛物线y2=-4x的准线方程为x=1,
∵双曲线
x2
a2
-
y2
b2
=1(a>0,b>0)的两条渐近线与抛物线y2=-4x的准线分别交于P,Q两点,
∴P,Q两点的纵坐标分别是y=
b
a
和y=-
b
a

∵△OPQ的面积等于3,∴
1
2
×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
±
b
a
bbbaaax,
又∵抛物线y22=-4x的准线方程为x=1,
∵双曲线
x2
a2
-
y2
b2
=1(a>0,b>0)的两条渐近线与抛物线y2=-4x的准线分别交于P,Q两点,
∴P,Q两点的纵坐标分别是y=
b
a
和y=-
b
a

∵△OPQ的面积等于3,∴
1
2
×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
x2
a2
x2x2x22a2a2a22-
y2
b2
=1(a>0,b>0)的两条渐近线与抛物线y2=-4x的准线分别交于P,Q两点,
∴P,Q两点的纵坐标分别是y=
b
a
和y=-
b
a

∵△OPQ的面积等于3,∴
1
2
×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
y2
b2
y2y2y22b2b2b22=1(a>0,b>0)的两条渐近线与抛物线y22=-4x的准线分别交于P,Q两点,
∴P,Q两点的纵坐标分别是y=
b
a
和y=-
b
a

∵△OPQ的面积等于3,∴
1
2
×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
b
a
bbbaaa和y=-
b
a

∵△OPQ的面积等于3,∴
1
2
×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
b
a
bbbaaa,
∵△OPQ的面积等于3,∴
1
2
×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
1
2
111222×1×2×
b
a
=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
b
a
bbbaaa=3,
∴b=3a,c=
10
a,
∴e=
c
a
=
10

故选:B.
10
10
1010a,
∴e=
c
a
=
10

故选:B.
c
a
cccaaa=
10

故选:B.
10
10
1010.
故选:B.