问题 问答题

已知椭圆

,F为其左焦点,离心率为e.若抛物线y2=8x的准线经过F点,椭圆C经过点P(2,3),求此椭圆的方程.

答案

参考答案:

解:抛物线y2=8x的准线为x=-2,所以F(-2,0),椭圆焦点与原点的距离c=2.所以4=a2-b2①,又因为椭圆C经过点P(2,3),所以

,结合①和②可得a2=16,b2=12,椭圆方程为

单项选择题 B1型题
填空题


Dear Sirs,
I am writing to your office to attempt to determine why I have encouraged so many obstacles to receiving my proper monthly social allotment. (1) The trouble occurred ten months ago and has actually gotten worse, making extremely difficult for me to meet normal financial obligations. (2) The first problem which I had to deal was simply getting a monthly check from you, without having to wait for four or five extra weeks for it. Then two of the checks that have arrived (3) made out for the wrong amount, giving me fifty dollars fewer than I should have received. (4) Another check was mailed to me at an address, which I moved more than two years ago. (5) My letter of inquiry, which I sent to the Los Angeles Office of the Social Security administration, never brought the answer, and when I finally telephoned them I was able to talk with an arrogant clerk (6) from the tone of his voice I could tell that he didn’t want to be bothered with me. The final blow is a letter received from your office yesterady in which you state that (7) my allotment is being discontinued, your records indicated that I am legally dead.
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Sincerely yours,
Thelma Spencer