已知a,b,c属于R,a+b+c=0,abc＞0,T=1/a+1/b+1/c,则________(答案T＜0),证明,老师讲的,T=1/a+1/b1/c=-(a^2+c^2-ac)/abc,

已知a,b,c属于R,a+b+c=0,abc＞0,T=1/a+1/b+1/c,则________(答案T＜0),证明,老师讲的,T=1/a+1/b1/c=-(a^2+c^2-ac)/abc,
已知a,b,c属于R,a+b+c=0,abc＞0,T=1/a+1/b+1/c,则________(答案T＜0),证明,老师讲的,T=1/a+1/b1/c=-(a^2+c^2-ac)/abc,

已知a,b,c属于R,a+b+c=0,abc＞0,T=1/a+1/b+1/c,则________(答案T＜0),证明,老师讲的,T=1/a+1/b1/c=-(a^2+c^2-ac)/abc,
a^2+c^2-ac=（a^2-ac+c^2/4）+3c^2/4
=(a-c/2)^2+3c^2/4
>0
abc＞0
∴ T=1/a+1/b+1/c=-(a^2+c^2-ac)/abc