记 cost = 2/√7, sint = √3/√7, 则 t = arctan(√3/2) = π/6
(2+√3)^2013 + (2-√3)^2014
= [√7(cost+sint)]^2013 + [√7(cost-sint)]^2014
= 7^(2013/2)(cos2013t + sin2013t) + 7^(1007)(cos2014t - sin2014t)
= 7^(2013/2)[cos(336-1/2)π + sin(336-1/2)π]
+ 7^(1007)[cos(336-1/3)π - sin(336-1/3)π]
= - 7^(2013/2) + 7^(1007)(1/2+√3/2) = 7^1006 (7/2+7√3/2-√7)
要是乘还可以算
加没啥技巧吧
解:这道题目可能有误,中间应该是乘号,而不应是加号,如果是加号恐怕就上电脑算了,我这里只作乘号化简仅供作参考
(2十v3)^2013*(2一√3)^2013*(2一√3)=((2十√3)(2一v3)^2013*(2一√3)
=(4一3)^2013*(2一√3)
=2一√3