當(dāng)焦點(diǎn)在x軸時(shí)
漸近線斜率是±b/a
b/a=1/2
b^2/a^2=1/4
c^2/a^2=5/4
e=c/a=√5/2
當(dāng)焦點(diǎn)在y軸時(shí)
漸近線斜率是±a/b
a/b=1/2
a^2/b^2=1/4
b^2/a^2=4
c^2/a^2=5
e=c/a=√5