问题
填空题
已知曲线
|
答案
设p(x1,y1);Q(x2,y2)
∵
•OP
=0OQ
∴kop*koq=-1即;y1y2=-x1x2
联立两方程:(b-a)x2+2ax-a-ab=0
x1+x2=2a a-b
x1x2=a+ab a-b
y1y2=1-(x1+x2)+x1x2=-x1x2
即2ab=b-a
∴1/a-1/b=2
-1 a
=1 b
=2b-a ab
故答案为2
已知曲线
|
设p(x1,y1);Q(x2,y2)
∵
•OP
=0OQ
∴kop*koq=-1即;y1y2=-x1x2
联立两方程:(b-a)x2+2ax-a-ab=0
x1+x2=2a a-b
x1x2=a+ab a-b
y1y2=1-(x1+x2)+x1x2=-x1x2
即2ab=b-a
∴1/a-1/b=2
-1 a
=1 b
=2b-a ab
故答案为2