题目 应为 a/(b+2c)+b/(c+2a)+c/(a+2b)≥1这道题可以利用Cauchy-Schwarz不等式做[a/(b+2c)+b/(c+2a)+c/(a+2b)]*(3ab+3bc+3ac)= [a/(b+2c)+b/(c+2a)+c/(a+2b)]*[a(b+2c)+b(c+2a)+c(a+2b)]≥(a+b+c)^2a/(b+2c)+b/(c+2a...