x1减x2的绝对值 x1减x2的绝对值
x1-x\u4e8c\u7684\u7edd\u5bf9\u503c\u4f60\u662f\u60f3\u95eex1-x\u4e8c\u7684\u7edd\u5bf9\u503c\u662f\u4ec0\u4e48\u5417\uff1fx1-x\u4e8c\u7684\u7edd\u5bf9\u503c\u662f|x1-x2|=\u221a(x1-x2)?=\u221a[(x1+x2)?-4x1x2]=\u221a(b?/a?-4c/a)=[\u221a(b?-4ac)]/|a|\u3002\u7edd\u5bf9\u503c\u662f\u6307\u4e00\u4e2a\u6570\u5728\u6570\u8f74\u4e0a\u6240\u5bf9\u5e94\u70b9\u5230\u539f\u70b9\u7684\u8ddd\u79bb\uff0c\u7528\u201c||\u201d\u6765\u8868\u793a\u3002
x1\u51cfx2\u7684\u7edd\u5bf9\u503c=[\u221a(b²-4ac)]/|a|
|x1-x2|=\u221a(x1-x2)²
=\u221a[(x1+x2)²-4x1x2]
=\u221a(b²/a²-4c/a)
=[\u221a(b²-4ac)]/|a|
\u6839\u636e\u4e00\u5143\u4e8c\u6b21\u65b9\u7a0bax²+bx+c=0(a\u22600)
x1+x2=-b/a
x1*x2=c/a
\u6240\u4ee5
|x1-x2|=\u221a(x1-x2)²
=\u221a[(x1+x2)²-4x1x2]
=\u221a(b²/a²-4c/a)
=[\u221a(b²-4ac)]/|a|
\u65e0\u7b26\u53f7\u6570\u8ba1\u7b97
\u5982\u679c\u628a\u4e09\u4e2a\u5973\u6027\u8bb0\u4e3a-3\uff0c\u628a\u56db\u4e2a\u7537\u6027\u8bb0\u4e3a+4\uff0c\u95ee\u6709\u51e0\u4e2a\u4eba\uff0c\u8ba1\u7b97\u65b9\u6cd5\u662f\u4e24\u4e2a\u6570\u7684\u7edd\u5bf9\u503c\u76f8\u52a0\uff0c\u4e5f\u5c31\u662f7\u4e2a\u4eba\u3002\u5982\u679c\u95ee\u7537\u5973\u5dee\u662f\u591a\u5c11\uff0c\u8ba1\u7b97\u65b9\u6cd5\u662f\u76f8\u5bf9\u6570\u76f8\u52a0\uff0c\u662f+1\u3002
\u5982\u679c\u628a\u5411\u5357\u8d701\u516c\u91cc\u8bb0\u4e3a+1\uff0c\u628a\u5411\u5317\u8d702\u516c\u91cc\u8bb0\u4e3a-2\uff0c\u95ee\u8d70\u4e86\u591a\u5c11\u516c\u91cc\uff0c\u8ba1\u7b97\u65b9\u6cd5\u662f\u4e24\u4e2a\u6570\u7684\u7edd\u5bf9\u503c\u76f8\u52a0\uff0c\u4e5f\u5c31\u662f3\u516c\u91cc\u3002\u5982\u679c\u95ee\u76f8\u5bf9\u8d70\u4e86\u591a\u5c11\u516c\u91cc\uff0c\u8ba1\u7b97\u65b9\u6cd5\u662f\u76f8\u5bf9\u6570\u76f8\u52a0\uff0c\u662f-1\u3002
\u5982\u679c\u628a\u5411\u96f6\u4e0a\u768410\u5ea6\u8bb0\u4e3a+10\uff0c\u628a\u96f6\u4e0b5\u5ea6\u8bb0\u4e3a-5\uff0c\u4e0a\u4e0b\u5dee\u591a\u5c11\u5ea6\uff0c\u8ba1\u7b97\u65b9\u6cd5\u662f\u4e24\u4e2a\u6570\u7684\u7edd\u5bf9\u503c\u76f8\u52a0\uff0c\u4e5f\u5c31\u662f15\u5ea6\u3002\u5982\u679c\u95ee\u6e29\u7684\u548c\u662f\u591a\u5c11\u5ea6\uff0c\u8ba1\u7b97\u65b9\u6cd5\u5c31\u662f\u76f8\u5bf9\u6570\u76f8\u52a0\uff0c\u662f+5\u3002
|x1-x2|=√(x1-x2)²
=√[(x1+x2)²-4x1x2]
=√(b²/a²-4c/a)
=[√(b²-4ac)]/|a|
根据一元二次方程ax²+bx+c=0(a≠0)
x1+x2=-b/a
x1*x2=c/a
所以
|x1-x2|=√(x1-x2)²
=√[(x1+x2)²-4x1x2]
=√(b²/a²-4c/a)
=[√(b²-4ac)]/|a|
扩展资料：
一元二次方程成立必须同时满足是整式方程，即等号两边都是整式，方程中如果有分母；且未知数在分母上，那么这个方程就是分式方程，不是一元二次方程。
方程中如果有根号，且未知数在根号内，那么这个方程也不是一元二次方程（是无理方程）。只含有一个未知数；未知数项的最高次数是2。
绛旓細鎵闂潪鎵绛 x1-x2缁濆鍊=鏍瑰彿涓媥1-x2瀹屽叏骞虫柟 灞曞紑寰楀埌(x1+x2)2-4x1x2 甯屾湜鑳藉府鍒颁綘
绛旓細|x1-x2| =鈭(x1-x2)²=鈭歔(x1+x2)²-4x1x2]
绛旓細鍥犱负x1锛x2鐨澶у皬鍏崇郴涓嶆槑纭紝鎵浠x1锛峹2|锛6 涓よ竟骞虫柟寰 x1²锛2x1x2+x2²锛36 (x1+x2)²锛4x1x2锛36 x1+x2涓巟1x2鍙牴鎹牴涓庣郴鏁扮殑鍏崇郴寰楀埌
绛旓細闊﹁揪鍏紡鐨勮繍鐢 x1-x2鐨勭粷瀵瑰涓鍏冧簩娆℃柟绋嬩腑浠ｈ〃涓や釜鏍瑰湪鏁拌酱涓婄殑璺濈锛屽洜涓猴紙X1+X2锛塣2-4X1*X2=X1^2+X2^2-2X1*X2=(x1-x2)^2 鎵浠ュ氨鐢▅(x1-x2)|=(锛圶1+X2锛塣2-4X1*X2)^1/2 鍐嶇粨鍚堥煢杈惧畾鐞嗘潵姹傚嚭x1-x2鐨勭粷瀵瑰 ...
绛旓細|x1-x2|=鈭氾紙x1+x2锛塣2-4x1x2 鐒跺悗澶ф鏄埄鐢ㄤ簩鍏冧竴娆℃柟绋嬫牴涓庣郴鏁扮殑鍏崇郴锛屽彲浠ュ緱 x1+x2=D x1x2=F 甯﹀叆鍗冲彲銆
绛旓細瑙:鈭x1锛x2婊¤冻缁濆鍊锛X1-X2锛=鈭5,鈭(x1-x2)^2=5,鈭x1.x2骞冲潎鏁版槸x=(x1+x2)/2.鈭存柟宸=[(x1-x)^2+(x2-x)^2]/2 =[(x1-x2)^2/4+(x2-x1)^2/4]/2 =[2(x1-x2)^2/4]/2 =(x1-x2)^2/4 =5/4
绛旓細鍥犱负 锛x1+x2锛夌殑骞虫柟-4x1x2=(x1鐨勫钩鏂+x2鐨骞虫柟+2x1x2)-4x1x2=x1鐨勫钩鏂+x2鐨勫钩鏂-2x1x2=(x1-x2)鐨勫钩鏂
绛旓細(x1涓x2)鐨勭粷瀵瑰 鎴戞潵绛 1涓洖绛 #鐑# 浣犲彂鏈嬪弸鍦堜細浣跨敤閮ㄥ垎浜哄彲瑙佸姛鑳藉悧? 鍖垮悕鐢ㄦ埛 2014-07-16 灞曞紑鍏ㄩ儴 鏇村杩介棶杩界瓟 杩界瓟 鑲畾瀵 璇烽噰绾 宸茶禐杩 宸茶俯杩< 浣犲杩欎釜鍥炵瓟鐨勮瘎浠锋槸? 璇勮 鏀惰捣 涓轰綘鎺ㄨ崘: 鐗瑰埆鎺ㄨ崘 鎽搁奔涓轰粈涔堜篃浼氱劍铏? 涓鍒嗛挓鐨凪BTI鎬ф牸娴嬭瘯闈犺氨鍚? 涓婃捣涓轰粈涔堟湁...
绛旓細涓鍏冧簩娆℃柟绋媋x²+bx+c=0(a鈮0)x1+x2=-b/a x1*x2=c/a |x1-x2|=鈭(x1-x2)²=鈭歔(x1+x2)²-4x1x2]=鈭(b²/a²-4c/a)=[鈭(b²-4ac)]/|a|
绛旓細瑙ｏ細鐢遍煢杈惧畾鐞嗭紝X1+X2=-a/b=-2 X1X2=a/c=-3/2 鍥犱负缁濆鍊閲屼竴瀹氭槸姝ｇ殑锛屽紑鏂逛篃涓瀹氭槸姝ｇ殑锛屾墍浠ョ粷瀵瑰间笉绠″畠涔熸槸涓鏍风殑銆俋1-X1=锛圶1+X2)²-4X1X2鐨宸啀寮鏂=鏍瑰彿10
