車貝契夫不等式有兩個(1)設存在數列a1,a2,a3.....an和b1,b2,b3......bn滿足a1≤a2≤a3≤.....≤an和b1≤b2≤b3≤......≤bn那么,∑AIBI≥(1/n)(∑ai)(∑bi)(2)設存在數列a1,a2,a3.....an和b1,b2,b3......bn滿足a1≤a2≤a3≤.....≤an和b1≥b2≥b3≥......≥bn那么,∑aibi≤(1/n)(∑ai)(∑bi)