Question

已知椭圆C以F1(-2,0)F2(2,0)为焦点且经过P(-5/2,3/2) (1)求椭圆方程(2)若斜率为1的直线L和

Answer 1

c = 2

x^2 / a^2 + y^2 / (a^2 - c^2) = 1

25/(4a^2) + 9/(4(a^2-c^2)) = 1

solve a = sqrt(10)

x^2/10 + y^2 / 6 = 1