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双曲线×2/8 - Y 2/16 = 1,A = 3,B = 4,C =√(3 2 4 2)= 5
两个焦点坐标:F1(-5,0), F2(5,0)
| | PF1 | - | PF2 | | = 2A = 6①
直角△PF1F2中,| PF1 | 2 + | PF2 | 2 = | F1F2 | 2; =(2C)2 = 100②
② - ①2是:2 | PF1 | * | PF2 | = 100-36 = 64
△PF1F2面积S = | PF1 | * | PF2 | / 2 = 64/4 = 16
P到x轴的距离H = 2S / | F1F2 | = 32/10 = 3.2
1年前
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