07选择题5★★☆☆☆
椭圆 x25+y2=1\frac{x^2}{5} + y^2 = 1, PPCC 上, PF1PF2=0\overrightarrow{PF_1} \cdot \overrightarrow{PF_2} = 0, 则 PF1PF2=|PF_1| \cdot |PF_2| = ( )
A.
11
B.
22
C.
44
D.
55
答案与解析

答案已隐藏