a=根号3,c=根号2,则汪腊b^2=a^2-c^2=1椭圆方程是x^2/3+y^2=1.圆半径=根号困辩滑(3+1)=2圆方灶芦程是x^2+y^2=4. (2)设P(m,n),L方程是y=k(x-m)+n.代入椭圆方程,令判别式=0.求得k1,k2.又m^2+n^2=4得k1k2=-1L1垂直于L2