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已知三角形ABC的三边A,B,C,满足A²=B² 判...

a²-ac=b²-bc a²-b&

方程判别式=(c²-a²-b²)

a²+b²+2c²=4a+6b+8c-21

http://www.jyeoo.com/math/ques/detail/11d38cbb-980

解: a²+b²+c²+388=10a+24

a²-b²=ac-bc (a+b)(a-b)=(a-b)c

B步骤是错误的 c²a²-b²)=(a&a

已知(a-b)(sinA+sinB)=(c-b)sinC 由正弦定理有:a/sinA=b/sinB

∵a b c为△ABC三边 ∴a>0 b>0 c>0 ∵ a2(c2-a2)=b2(

根据余弦定理有 cos∠A = (b² + c² - a&

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