=[(3x1-2-4)^2+(3x2-2-4)^2+(3x3-2-4)^2+(3x4-2-4)^2+(3x5-2-4)^2]/5=9[(x1-2)^2+(x2-2)^2+(x3-2)^2+(x4-2)^2+(x5-2)^2]/5这步怎么算的 最后一步一步分析
来源:学生作业帮助网 编辑:六六作业网 时间:2025/02/01 02:17:21
=[(3x1-2-4)^2+(3x2-2-4)^2+(3x3-2-4)^2+(3x4-2-4)^2+(3x5-2-4)^2]/5=9[(x1-2)^2+(x2-2)^2+(x3-2)^2+(x4-2)^2+(x5-2)^2]/5这步怎么算的 最后一步一步分析
=[(3x1-2-4)^2+(3x2-2-4)^2+(3x3-2-4)^2+(3x4-2-4)^2+(3x5-2-4)^2]/5=9[(x1-2)^2+(x2-2)^2+(x3-2)^2+(x4-2)^2+(x5-2)^2]/5这步怎么算的 最后一步一步分析
=[(3x1-2-4)^2+(3x2-2-4)^2+(3x3-2-4)^2+(3x4-2-4)^2+(3x5-2-4)^2]/5=9[(x1-2)^2+(x2-2)^2+(x3-2)^2+(x4-2)^2+(x5-2)^2]/5这步怎么算的 最后一步一步分析
[(3x1-2-4)^2+(3x2-2-4)^2+(3x3-2-4)^2+(3x4-2-4)^2+(3x5-2-4)^2]/5=[(3x1-6)^2+(3x2-6)^2+(3x3-6)^2+(3x4-6)^2+(3x5-6)^2]/5=[(3x1-3*2)^2+(3x2-3*2)^2+(3x3-3*2)^2+(3x4-3*2)^2+(3x5-3*2)^2]/5={[3(X1-2)]^2+[3(x2-2)]^2+[3(x3-2)]^2+[3(x4-2)]^2+[3(x5-2)]^2}/5=9[(x1-2)^2+(x2-2)^2+(x3-2)^2+(x4-2)^2+(x5-2)^2]/5
简单说就是把-2-4变成-6,然后变成-(2*3),再把3提出来,平方得9,后面的就是(X-2)了.
=[(3x1-2-4)^2+(3x2-2-4)^2+(3x3-2-4)^2+(3x4-2-4)^2+(3x5-2-4)^2]/5
=[(3x1-6)^2+(3x2-6)^2+(3x3-6)^2+(3x4-6)^2+(3x5-6)^2]/5
=[3^2(x1-2)^2+3^2(x2-2)^2+3^2(x3-2)^2+3^2(x4-2)^2+3^2(x5-2)^2]/5
=[9(x1-2)^2+9(x2-2)^2+9(x3-2)^2+9(x4-2)^2+9(x5-2)^2]/5
=9[(x1-2)^2+(x2-2)^2+(x3-2)^2+(x4-2)^2+(x5-2)^2]/5