设a,b,c∈(0,1) 求证a+b
设a,b,c大于0,求证c/(a+b)+a/(b+c)+b/(c+a)大于等于3/2.
设a,b,c∈R,a+b+c等于o,abc<0,求证1/a+1/b+1/c>O
设a,b,c∈R,a+b+c等于o,abc>0,求证1/a+1/b+1/c
设a,b,c∈R和a+b+c等于o,abc<0,求证1/a+1/b+1/c>O
设a,b,c∈R,a+b+c等于o,abc>0,求证1/a+1/b+1/c<O
设a>b>c,且a+b+c=0,求证:√(b^2-ac)
设a,b,c∈[-1,1],求证ab+bc+ac+1≥0,
设a>0,b>0,2c>a+b,求证:c-根号下(c^2 - ab)
设a>0,b>0,2c>a+b,求证:c-c
设a、b、c均为正实数,求证:三个数a+1b
设A.B.C均为正数,求证c/(a+b)+a/(b+c)+b/(c+a)>=3/2
设a,b,c,属于正实数,求证a/(b+c)+b/(c+a)+c/(a+b)>=2/3