Contact us
Choose a category below so we can get back to you as quickly as possible.
設雙曲線為X~2/a~2-Y~2/a~2=1任意點(X0,Y0)點到中心的距離的平方等於X0~2+Y0~2因為X~2-Y~2=a~2兩邊同加X~2+Y~2-a~2得X0~2+Y0~2=2X0~2-a~2點到兩焦點的乘積等於|(ex+a)(ex-a)|因為e=根號2所以|(eX0+a)(eX0-…
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.