设椭圆的方程为x^/a^+y^/b^=1
与y=x+1连立
P(x1,y1) Q(x2,y2)
x^/a^+(x+1)^/b^=1
x1+x2=-2b^/(1/a^+1/b^) x1x2=(1/b^-1)/(1/a^+1/b^)
OP⊥OQ
x1x2+y1y2=0
x1x2+(x1+1)(x2+1)=0
2x1x2+(x1+x2)+1=0
带入可得1/a^+1/b^=2
e=√2/2=c/a
c^/a^=1/2
b^/a^=1/2
b^=3/4
a^=3/2
x^/(3/2)+y^/(3/4)=1