Pure Mathematics - Proof

2007-09-18 6:05 am

By completing the square, prove that x^2 + xy + y^2 = 0 <=> x = 0 or y = 0.
Don't know how to prove...
Thank you very much!

回答 (1)

2007-09-18 6:28 am

✔ 最佳答案

As follows:

圖片參考：http://i117.photobucket.com/albums/o61/billy_hywung/Sep07/Crazyeqn11.jpg

2007-09-18 14:09:08 補充：
In the proof, we just use the fact and the proof can be skipped for "All square of real numbers are non-negative".

參考: My Maths knowledge

👍 0 👎 0