（a+b+c）的二次方 （a+b+c）的二次方计算过程
abc\u7684\u548c\u7684\u5e73\u65b9\u516c\u5f0f\uff08a\uff0bb\uff0bc\uff09\u7684\u5e73\u65b9\uff08a+b+c\uff09²
=\uff08a+b+c\uff09\u00b7\uff08a+b+c\uff09
=a²+ab+ac+b²+ab+bc+c²+ac+bc
=a²+b²+c²+2ab+2ac+2bc
\u5e73\u65b9\u662f\u4e00\u79cd\u8fd0\u7b97\uff0c\u6bd4\u5982\uff0ca\u7684\u5e73\u65b9\u8868\u793aa\u00d7a\uff0c\u7b80\u5199\u6210a²\uff0c\u4e5f\u53ef\u5199\u6210a\u00d7a(a\u7684\u4e00\u6b21\u65b9\u4e58a\u7684\u4e00\u6b21\u65b9\u7b49\u4e8ea\u76842\u6b21\u65b9\uff09\uff0c\u4f8b\u59824\u00d74=16\uff0c8\u00d78=64\uff0c\u5e73\u65b9\u7b26\u53f7\u4e3a²\u3002
\u6269\u5c55\u8d44\u6599\uff1a\u8bfb\u97f3\uff1ap\u00edng f\u0101ng \uff0c\u8bb0\u4f5c\uff1a²\uff0c\u4f8b\u5982x²\u3002\uff08\u6ce8\uff1a\u7535\u8111\u4e0a\u53ef\u7528\u201c^\u201d\u4ee3\u66ff\uff0c\u4f8b\u5982x^2\u5c31\u662fx²\u7684\u610f\u601d\uff09
\u73b0\u4ee3\u6c49\u8bed\u8bcd\u5178\u91ca\u4e49\uff1a
\u2460\u6307\u6570\u662f2\u7684\u4e58\u65b9\u3002
\u2461\u6307\u5e73\u65b9\u7c73\u3002
\u8fb9\u957f\u7684\u5e73\u65b9\uff08\u5373\u8fb9\u957f\u00d7\u8fb9\u957f\uff09=\u6b63\u65b9\u5f62\u7684\u9762\u79ef\u3002\u5e73\u65b9\u53c8\u53eb\u4e8c\u6b21\u65b9\uff0c\u5e73\u65b9\u7684\u9006\u8fd0\u7b97\u5c31\u662f\u5f00\u5e73\u65b9,\u4e5f\u53eb\u505a\u6c42\u5e73\u65b9\u6839\uff0c\u5e73\u65b9\u6839\u5199\u4f5c\uff1a\u00b1\u221a\uff0c\u4f8b\u5982\u00b1=\u00b11.7320\u2026\u2026\uff0c\u800c\u6b63\u597d\u00b11.7320\u2026\u2026\u7684\u5e73\u65b9\u662f3\u3002\u800c
\u79f0\u4e4b\u4e3a\u7b97\u672f\u5e73\u65b9\u6839\uff0c\u4f8b\u5982=1.7320.......\u3002
\u2462\u5e73\u65b9\u7b49\u4e8e\u5b83\u672c\u8eab\u7684\u6570\u53ea\u67090\u548c1\u3002
\u2463\u4e00\u4e2a\u6570\u7684\u5e73\u65b9\u5177\u6709\u975e\u8d1f\u6027\u3002\u5373a²\u22650.\u5e94\u7528\uff1a\u82e5a²+b²=0,\u5219\u6709a=0\u4e14b=0\u3002
\u53c2\u8003\u8d44\u6599\uff1a\u5e73\u65b9-\u767e\u5ea6\u767e\u79d1
[\u5c0f\u82b1]\u5b66\u9738\u4e13\u5c5e\u65b9\u6cd5\uff0c\u8ba1\u7b97\uff1a\uff08a+b+c\uff09²\uff0c\u65b9\u6cd5\u771f\u662f\u5999
a的二次方加b的二次方加c的二次方加3ab加2ac加bc
2a^2+2b^2+2c^2+2ab+2ac+2bc
绛旓細鍘熷紡=a²b²c²
绛旓細A鐨勪簩娆℃柟鏄2锛孊鐨勪笁娆℃柟鏄3锛孋鐨勪簲娆℃柟鏄5 鍒橝涓烘牴鍙2=1.414锛宐涓3娆℃牴鍙3=1.44锛宑涓5娆℃牴鍙5=1.379 鍒檅澶т簬a澶т簬c
绛旓細鍦ㄢ柍ABC涓紝鏈夛細a锛2锛b锛2锛媍锛2涓2bccosA锛岃繖涓叕寮忕О涓轰綑寮﹀畾鐞嗭紒瀹冩槸鐩稿浜庢寮﹀畾鐞嗚屾彁宀鏉ョ殑锛屼竴鑸潵璇达紝杩欐牱鐨勫叕寮忥紝鍙姹傚鐢熻浣忓拰杩愮敤锛屼笉闇瑕佽冧綘鏄庝箞鍘昏瘉鏄庡畠鐨勩
绛旓細缁濆鍊硷紝骞虫柟锛屾牴鍙烽兘鏄潪璐熸暟锛屽彧鏈0+0+0=0
绛旓細锛坅+b+c锛夌殑浜屾鏂璁＄畻杩囩▼濡備笅 锛氬畬鍏ㄥ钩鏂瑰叕寮忓嵆(a+b)²=a²+2ab+b²銆(a-b)²=a²-2ab+b²銆傝鍏紡鏄繘琛屼唬鏁拌繍绠椾笌鍙樺舰鐨勯噸瑕佺殑鐭ヨ瘑鍩虹锛屾槸鍥犲紡鍒嗚В涓父鐢ㄥ埌鐨勫叕寮忋傝鐭ヨ瘑鐐归噸鐐规槸瀵瑰畬鍏ㄥ钩鏂瑰叕寮忕殑鐔熻鍙婂簲鐢ㄣ傞毦鐐规槸瀵瑰叕寮忕壒寰佺殑鐞嗚В(濡傚鍏紡涓Н...
绛旓細(a+b+c)^2=a^2+b^2+c^2+2ab+2bc+2ac銆傜畝浠嬶細娆℃柟锛堜唬鏁版湳璇細寮鏂癸級鏈鍩烘湰鐨勫畾涔夋槸锛氳a涓烘煇鏁帮紝n涓烘鏁存暟锛宎鐨刵娆℃柟琛ㄧず涓篴ⁿ锛岃〃绀簄涓猘杩炰箻鎵寰椾箣缁撴灉锛屽2⁴=2脳2脳2脳2=16銆傛鏂圭殑瀹氫箟杩樺彲浠ユ墿灞曞埌0娆℃柟鍜岃礋鏁版鏂圭瓑绛夈傚湪鐢佃剳涓婅緭鍏ユ暟瀛﹀叕寮忔椂锛屽洜涓轰笉渚夸簬杈撳叆...
绛旓細瑙ｆ瀽杩囩▼锛锛坅+b+c锛夌殑2娆℃柟=[(a+b)+c]=(a+b)+2(a+b)c+c=a+b+c+2ab+2bc+2ca锛屽钩鏂规槸涓绉嶈繍绠楋紝姣斿锛宎鐨勫钩鏂硅〃绀篴脳a锛岀畝鍐欐垚a锛屼篃鍙啓鎴恆脳a锛坅鐨勪竴娆℃柟涔榓鐨勪竴娆℃柟绛変簬a鐨2娆℃柟锛夛紝渚嬪4脳4=16锛8脳8=64锛屽钩鏂圭鍙蜂负2銆傚畬鍏ㄥ钩鏂瑰紡 瀹屽叏骞虫柟寮忔槸鎸囧鏋滄弧瓒冲浜庝竴涓叿鏈...
绛旓細(a+b+c)²锛歛²+b²+c²+2ab+2bc+2ca銆傚钩鏂规槸涓绉嶈繍绠楋紝姣斿锛宎鐨勫钩鏂硅〃绀篴脳a锛岀畝鍐欐垚a锛屼篃鍙啓鎴恆脳a(a鐨勪竴娆℃柟涔榓鐨勪竴娆℃柟绛変簬a鐨2娆℃柟锛夛紝渚嬪4脳4=16锛8脳8=64锛屽钩鏂圭鍙蜂负2銆傜浉鍏充俊鎭細涔樻硶鍏紡灏嗕竴浜涚壒娈婄殑澶氶」寮忕浉涔樼殑缁撴灉鍔犱互鎬荤粨锛岀洿鎺ュ簲鐢ㄣ傚叕寮忎腑鐨勬瘡...
绛旓細瑙ｏ細(a+b+c)²=(a+b+c)(a+b+c) (澶氶」寮忎箻澶氶」寮忥紝鎶婁竴涓椤瑰紡鐨勬瘡涓椤瑰幓涔樺彟涓涓椤瑰紡鐨勬瘡涓椤癸紝鍐嶆妸绉浉鍔狅級=a²+ab+ac+ab+b²+bc+ac+bc+c²=a²+b²+c²+2ab+2ac+2bc
绛旓細=锛坅+b+c锛路锛坅+b+c锛=a²+ab+ac+b²+ab+bc+c²+ac+bc =a²+b²+c²+2ab+2ac+2bc 骞虫柟鏄竴绉嶈繍绠楋紝姣斿锛宎鐨勫钩鏂硅〃绀篴脳a锛岀畝鍐欐垚a²锛屼篃鍙啓鎴恆脳a(a鐨勪竴娆℃柟涔榓鐨勪竴娆℃柟绛変簬a鐨2娆℃柟锛夛紝渚嬪4脳4=16锛8脳8=64锛屽钩鏂圭鍙蜂负²...
