Contact us
Choose a category below so we can get back to you as quickly as possible.
x^2/a-y^2/b=1 x^2+y^2=d 寫出焦點的座標,計算兩焦點到P的的乘積,比較,可以驗算.
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.