a²+b²+c²-ab-bc-ac=½[(a-b)²+(b-c)²+(c-a)²]若a=2009,b=2010,c=2011,你能很快求出a²+b²+c²-ab-bc-ac的值吗?
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/21 16:57:22
![a²+b²+c²-ab-bc-ac=½[(a-b)²+(b-c)²+(c-a)²]若a=2009,b=2010,c=2011,你能很快求出a²+b²+c²-ab-bc-ac的值吗?](/uploads/image/z/210599-71-9.jpg?t=a%26%23178%3B%2Bb%26%23178%3B%2Bc%26%23178%3B-ab-bc-ac%3D%26%23189%3B%5B%28a-b%29%26%23178%3B%2B%28b-c%29%26%23178%3B%2B%28c-a%29%26%23178%3B%5D%E8%8B%A5a%3D2009%2Cb%3D2010%2Cc%3D2011%2C%E4%BD%A0%E8%83%BD%E5%BE%88%E5%BF%AB%E6%B1%82%E5%87%BAa%26%23178%3B%2Bb%26%23178%3B%2Bc%26%23178%3B-ab-bc-ac%E7%9A%84%E5%80%BC%E5%90%97%3F)
x)KTS64NZ71I7)Y71ȷHM҄HMKm,uN22ywOu<ݿƦ|Vӆ=O'LI*ҧ#ĥv6C%@
x1Y@3;Q7VH1iFZچ&c<;hڀ9X-6)B$n@ @'?m]
}Ӂ.V5Ԍ3҆RFqF`aw}`. &?
{#i CK
a²+b²+c²-ab-bc-ac=½[(a-b)²+(b-c)²+(c-a)²]若a=2009,b=2010,c=2011,你能很快求出a²+b²+c²-ab-bc-ac的值吗?
a²+b²+c²-ab-bc-ac=½[(a-b)²+(b-c)²+(c-a)²]
若a=2009,b=2010,c=2011,你能很快求出a²+b²+c²-ab-bc-ac的值吗?
a²+b²+c²-ab-bc-ac=½[(a-b)²+(b-c)²+(c-a)²]若a=2009,b=2010,c=2011,你能很快求出a²+b²+c²-ab-bc-ac的值吗?
a=2009,b=2010,c=2011
则:a-b=-1;a-c=-2;b-c=-1
a²+b²+c²-ab-bc-ac=½[(a-b)²+(b-c)²+(c-a)²]
=1/2*(1+1+4)
=3
3
根号6
a²+b²+c²-ab-bc-ac
=1/2*(1+1+4)
=3
a²+b²+c²-ab-bc-ac=½[(a-b)²+(b-c)²+(c-a)²]
a=2009,b=2010,c=2011
代入
得1/2[ (-1)^2+(-1)^2+2^2]=1/2*6=3
明明是3啊,怎么能算成根号6?