æ¹æ³1ï¼èèa=1/3=b=cçæ¶ååçå·ï¼åèèå°æ¬¡æ°ä¹é´çå·®å¼ï¼
å©ç¨x^2+y^2>=2xy
åå¯ä»¥é
a+(1/3)>=2 sqrtï¼a/3ï¼
åçb+(1/3)>=2 sqrtï¼b/3ï¼
c+(1/3)>=2 sqrtï¼c/3ï¼
æ以累å å¾å°ï¼sqrtï¼a/3ï¼+ sqrtï¼b/3ï¼+sqrtï¼c/3ï¼<=sqrtï¼3ï¼
第äºç§åæ³åæ¯ç´æ¥å©ç¨æ¯è¥¿ä¸çå¼çä¸å
å½¢å¼ï¼ï¼x^2+y^2+z^2ï¼ï¼l^2+m^2+n^2ï¼>=(xl+ym+zn)^2
æ以æï¼a+b+cï¼ï¼1+1+1ï¼>=ï¼sqrtï¼aï¼+ sqrtï¼bï¼+sqrtï¼cï¼ï¼^2
带å
¥æ¡ä»¶æ´çä¸ä¸çæ¡å°±åºæ¥äºã
å¯ä»¥èªå·±ç¾åº¦ä¸ä¸æ¯è¥¿ä¸çå¼ï¼å¦ä¹ ä¸ä¸ï¼äºå
çå½¢å¼ä½ 书ä¸æçã
温馨提示:答案为网友推荐,仅供参考