(a+b)³=a³+3a²b+3ab²+b³//如何证明?
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/21 03:59:09
![(a+b)³=a³+3a²b+3ab²+b³//如何证明?](/uploads/image/z/1268136-0-6.jpg?t=%28a%2Bb%29%26%23179%3B%3Da%26%23179%3B%2B3a%26%23178%3Bb%2B3ab%26%23178%3B%2Bb%26%23179%3B%2F%2F%E5%A6%82%E4%BD%95%E8%AF%81%E6%98%8E%3F)
(a+b)³=a³+3a²b+3ab²+b³//如何证明?
(a+b)³=a³+3a²b+3ab²+b³//如何证明?
(a+b)³=a³+3a²b+3ab²+b³//如何证明?
证明
(a+b)³
=(a+b)²(a+b)
=(a²+2ab+b²)(a+b)
=a³+a²b+2a²b+2ab²+b²a+b³
=a³+2a²b+3ab²+b³
命题得证
3a²b+3ab²+b³//如