三角形ABC中,角A角B.角C的对边分别为a.b..c,已知关于X的方程X平方-(c+4)X+4c+8==0
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三角形ABC中,角A角B.角C的对边分别为a.b..c,已知关于X的方程X平方-(c+4)X+4c+8==0
三角形ABC中,角A角B.角C的对边分别为a.b..c,已知关于X的方程X平方-(c+4)X+4c+8==0
三角形ABC中,角A角B.角C的对边分别为a.b..c,已知关于X的方程X平方-(c+4)X+4c+8==0
1)因为a,b是关于x的方程的两根
所以a+b=c+4,ab=4c+8
所以a^2+b^2=(a+b)^2-2ab=c^2
由余弦定理知cosC=(a^2+b^2-c^2)/(2ab)
将a^2+b^2=c^2代入可得cosC=0
所以角C=90度
题目没有完善,漏了点什么吧
题目不完整,一般这类题目,你可以根据方程有解的条件和三角形的一些隐性条件来求解,最好把题目补充完整了,大家才好帮你
题目不完整
The Ugg Boot or only Uggs namely some sort of generic term as just a manner of sheepskin shoe that's been produced with Australia and New Zealand for virtually 200 years. Originally the were creature ...
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