11/1 · gfhg

11/1 · 重新删除一遍

11/1 · Notice: Undefined index: m in /web/php/tieba/Include/Confirm.php on line 13

11/1 · 当x,y至少有1个为0时,不等式右边=0,左边≥0 不等式成立 当x,y均不为0时, xy(x+y)^2/2 =xy(x^2+2xy+y^2)/2 =(x^3y+2x^2y^2+xy^3)/2 ≤(x^3y+x^4+y^4+xy^3)/2 现在只要证明x^3y+xy^3≤x^4+y^4就可以了. x^3y+xy^3-x^4-y^4 =x^3(y-x)-y^3(y-x) =-(y^3-x^3)(y-x) =-(y-x)^2(y^2+xy+x^2) 由于(y-x)^2≥0 y^2+xy+x^2=(x...

11/1 · a√b=a²b

11/1 · rt

11/1 · 共有16套签名档

11/1 · 删除成功

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