e=c/a=2
c²=4a²
设PF1=m,PF2=n
|m-n|=2a
m²+n²-2mn=4a²
F1F2=2c
F1F2²=16a²
cos60=1/2=(m²+n²-16a²)/2mn
m²+n²-16a²=mn
12a²=mn
S=1/2mnsin60=3√3a²=12√3
a²=4
x²/4-y²/12=1
e=c/a=2
c²=4a²
设PF1=m,PF2=n
|m-n|=2a
m²+n²-2mn=4a²
F1F2=2c
F1F2²=16a²
cos60=1/2=(m²+n²-16a²)/2mn
m²+n²-16a²=mn
12a²=mn
S=1/2mnsin60=3√3a²=12√3
a²=4
x²/4-y²/12=1