If α and β are the roots of the equation x²-2x -6=0,find the values of α²+2β= ？
回答 (1)
2019-10-08 12:20 pm
α²+2β
=α²+2(α+β-α)
=α²+2(2-α)
=α²-2α+4
=(α²-2α-6)+10
=10
=α²+2(α+β-α)
=α²+2(2-α)
=α²-2α+4
=(α²-2α-6)+10
=10
收錄日期: 2021-04-11 23:00:46
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20191004145334AAOCO8E