若a,b,c>0,求证:1/2a+1/2b+1/2c>=1/(a+b)+1/(b+c)+1/(c+a)
..a b c为正,求证a^2/(b+c)+b^2/(c+a)+c^2/(a+b)>=1/2(a+b+c)
若a,b,c>0,求证:1/2a+1/2b+1/2c>=1/(a+b)+1/(b+c)+1/(c+a)
已知a>b>c,且2a+3b+4c=0.(1)求证:a+b+c>0
1.已知:a/b=(a-c)/(c-b),求证:1/a+1/b=2/c
已知a+b+c=1,a平方+b平方+c平方=3,a>b>c,求证 -2/3
a,b,c>0 ,a2+b2+c2+2abc=1 求证:a+b+c
已知a>b>c,求证1/(a-b)+1/(b-c)+1/(c-a)>0
1.计算:(1)(a-b)(a-c)分之2a-b-c + (b-c)(b-a)分之2b-c-a + (c-b)(c-a)
若a,b,c属于正实数,求证:1/2a+1/2b+1/2c≥1/(b+c)+1/(a+c)+1/(a+b)
已知a,b,c都是正实数,求证:1/2a+1/2b+1/2c>=1/(b+c)+1/(c+a)+1/(a+b)
a,b,c都是正数.求证:1/2a+1/2b+1/2c>=1/(a+b) + 1/(b+c) + 1/(a+c)
设a,b,c都是正数,求证1/2a+1/2b+1/2c>=1/(a+b)+1/(b+c)+1/(c+a)