三角形的三编长abc且满足8^a=8^b*2^c,log(2c)b+log(2c)(3a-2c)=2试判断三角形abc的形状,

问题描述:

三角形的三编长abc且满足8^a=8^b*2^c,log(2c)b+log(2c)(3a-2c)=2试判断三角形abc的形状,
rt

2^(3a)=2^(3b+c)3a=3b+clog2c(b)+log2c(3a-2c)=2=log2c(4c^2)log2c[(b*(3a-2c)]=log2c(4c^2)b(3a-2c)=4c^2b(3b+c-2c)=4c^23b^2-bc-4c^2=0(3b-4c)(b+c)=0b=4/3c3a=3b+c=4c+c=5ca=5/3c所以a:b:c=5:4:35^2=3^2+4^2所以...