曲线是个椭圆曲线,设解析式为
x 2
a 2 +
y 2
b 2 =1,(a>b)
截面与底面所成的角为30°,则:
2r
2a =cos30°
∴a=
2r
3
b=r
∴解析式为
3 x 2
4r +
y 2
r 2 =1
∴c=
a 2 - b 2 =
r
3
∴e=
c
a =
1
2
故答案为:椭圆,
1
2
曲线是个椭圆曲线,设解析式为
x 2
a 2 +
y 2
b 2 =1,(a>b)
截面与底面所成的角为30°,则:
2r
2a =cos30°
∴a=
2r
3
b=r
∴解析式为
3 x 2
4r +
y 2
r 2 =1
∴c=
a 2 - b 2 =
r
3
∴e=
c
a =
1
2
故答案为:椭圆,
1
2