已知雙曲線x2/9-y2/16=1的兩個(gè)焦點(diǎn)分別為F1、F2
已知雙曲線x2/9-y2/16=1的兩個(gè)焦點(diǎn)分別為F1、F2,點(diǎn)P為此..
已知雙曲線x2/9-y2/16=1的兩個(gè)焦點(diǎn)分別為F1、F2,點(diǎn)P為此雙曲線上一點(diǎn),|PF1|·|PF2|=32,求證:PF1⊥PF2
正確答案: 焦點(diǎn)坐標(biāo):F1(-5,0) F2(5,0)
PF1²+PF2²=|PF1-PF2|²+2|PF1||PF2| = 6²+2*32=10² = |F1F2|²
所以根據(jù)勾股定理,PF1⊥PF2源于查字典網(wǎng)
正確答案: 焦點(diǎn)坐標(biāo):F1(-5,0) F2(5,0)
PF1²+PF2²=|PF1-PF2|²+2|PF1||PF2| = 6²+2*32=10² = |F1F2|²
所以根據(jù)勾股定理,PF1⊥PF2源于查字典網(wǎng)