计算(X+Y+Z)平方
(x+y-z)\u7684\u5e73\u65b9\u600e\u4e48\u8ba1\u7b97(x+y-z)²
=(x+y-z)(x+y-z)
=x²+xy-xz+xy+y²-yz-xz-yz+z²
=x²+y²+z²+2xy-2yz-2xz
\u5f88\u9ad8\u5174\u4e3a\u60a8\u89e3\u7b54\uff0c\u795d\u4f60\u5b66\u4e60\u8fdb\u6b65\uff01\u3010\u5b66\u4e60\u5b9d\u5178\u3011\u56e2\u961f\u4e3a\u60a8\u7b54\u9898\u3002
\u6709\u4e0d\u660e\u767d\u7684\u53ef\u4ee5\u8ffd\u95ee\uff01\u5982\u679c\u60a8\u8ba4\u53ef\u6211\u7684\u56de\u7b54\u3002
\u8bf7\u70b9\u51fb\u4e0b\u9762\u7684\u3010\u9009\u4e3a\u6ee1\u610f\u56de\u7b54\u3011\u6309\u94ae\uff0c\u8c22\u8c22\uff01
(x+y+z)²
=[(x+y)+z]²
=(x+y)²+2(x+y)z+z²
=x²+2xy+y²+2xz+2yz+z²
=x²+y²+z²+2xy+2xz+2yz
\u9f99\u8005\u8f7b\u541f\u4e3a\u60a8\u89e3\u60d1,\u51e4\u8005\u8f7b\u821e\u95fb\u60a8\u8ffd\u95ee.
\u5982\u82e5\u6ee1\u610f,\u8bf7\u70b9\u51fb[\u6ee1\u610f\u7b54\u6848];\u5982\u82e5\u60a8\u6709\u4e0d\u6ee1\u610f\u4e4b\u5904,\u8bf7\u6307\u51fa,\u6211\u4e00\u5b9a\u6539\u6b63!
\u5e0c\u671b\u8fd8\u60a8\u4e00\u4e2a\u6b63\u786e\u7b54\u590d!
\u795d\u60a8\u5b66\u4e1a\u8fdb\u6b65!
(x+y+z)²=x²+y²+z²+2xy+2yz+2zx
等于X^2+Y^2+Z^2+2XY+2YZ+2XZ
X^2即X的平方
(X+Y+Z)²
=[(X+Y)+Z]²
=(X+Y)²+2(X+Y)Z+Z²
=X¹+2XY+Y²+2XZ+2YZ+Z²
绛旓細涓夐」鍜岀殑骞虫柟绛変簬鍚勯」骞虫柟鍜屽啀鍔犱笂姣忎袱椤逛箻绉殑2鍊嶃
绛旓細(x+y+z)^2=[(x+y)+z]^2 =(x+y)^2+2(x+y)z+z^2 =x^2+y^2+z^2+2xy+2xz+2yz.
绛旓細(x+y+z)²=x²+y²+z²+2xy+2yz+2zx
绛旓細(x+y+z)²=x²+y²+z²+2xy+2xz+2yz
绛旓細(x+y+z)²=x²+2xy+y²+2xz+z²+2yz銆傝В棰樻濊矾锛氫笁椤瑰拰鐨骞虫柟绛変簬鍚勯」骞虫柟鍜屽啀鍔犱笂姣忎袱椤逛箻绉殑2鍊嶃傚湪鏁板涓紝鐢辫嫢骞蹭釜鍗曢」寮忕浉鍔犵粍鎴愮殑浠ｆ暟寮忓彨鍋氬椤瑰紡銆傚椤瑰紡涓殑姣忎釜鍗曢」寮忓彨鍋氬椤瑰紡鐨勯」锛岃繖浜涘崟椤瑰紡涓殑鏈楂橀」娆℃暟锛屽氨鏄繖涓椤瑰紡鐨勬鏁般傚叾涓椤瑰紡涓笉鍚瓧姣嶇殑椤...
绛旓細涓夊厓瀹屽叏骞虫柟鍏紡鏄(x-y-z)²=x²+y²+z²-2xy-2xz+2yz锛屽畠鍙互鐢ㄦ潵璁＄畻涓涓暟鐨勫钩鏂癸紝骞朵笖鍙互鐢ㄤ簬瑙ｅ喅涓浜涙暟瀛﹂棶棰樸傝繖涓叕寮忕殑璇佹槑鍙互閫氳繃灞曞紑(x-y-z)²锛岀劧鍚庡埄鐢ㄥ钩鏂瑰樊鍏紡鍜屽畬鍏ㄥ钩鏂瑰叕寮忔潵璇佹槑銆傚叿浣撴潵璇达紝鎴戜滑鍙互灞曞紑(x-y-z)²锛屽緱鍒皒²-2xy-...
绛旓細鐩存帴灞曞紑鍢涖傘傘傦紳x^2+y^2+z^2-2xy-2yz+2xz鍟︺傘傘傝浣忎笁涓暟瀹屽叏骞虫柟灏辨槸姣忎釜鏁板钩鏂瑰拰鍔2鍊嶄袱涓や箻绉紙娉ㄦ剰甯︾鍙凤級銆傘傘
绛旓細(x+y+z)^2=x^2+y^2+z^2+2xy+2xz+2yz 璁＄畻杩囩▼濡備笅锛(x+y+z)^2 =(x+y)^2+2(x+y)z+z^2 =x^2+y^2+z^2+2xy+2xz+2yz
绛旓細z²=x²+y²锛坸锛寉锛寊鐨嗕负鍙橀噺锛夛紝鏄粈涔堢珛浣撳浘褰 瑙ｏ細浠=0锛屽緱x²+y²=0锛涙晠鍥惧儚杩囧師鐐(0锛0锛0)锛涗护z=卤a锛(a>0)鍗崇敤涓巟oy骞抽潰鐨勮窛绂讳负a涓斾笌xoy骞抽潰骞宠鐨勫钩闈㈠幓鎴鍥惧儚锛屽緱x²+y²=a²锛涘嵆鎴彛鏄崐寰勪负a锛屽洯蹇冨湪z杞翠笂鐨勫洯锛涗护...
绛旓細璁緔鏄痑鐨骞虫柟锛屽洜涓1002=10 000锛屾墍浠ュ彲浠ョ‘瀹歛鏄竴涓笁浣嶆暟锛庡洜涓2002=40 000锛屾墍浠浠嬩簬100鍒200涔嬮棿锛屽張鈭1702=28 900锛1802=32 400锛屸埓y搴旀槸澶т簬170鑰屽皬浜180鐨勪笁浣嶆暟锛屼笅闈㈠氨鍙互鐢ㄦ帰绱㈢殑鏂规硶浠171寮濮嬪幓璇曪紝鐩村埌鎵惧埌涓烘锛庨氳繃璁＄畻鍙緱a涓178锛庡嵆鍙璁＄畻y鐨勫间负31684锛
