来自刘海华的问题
【一道高一的数学计算题(1+(2^(-1/8)))*(1+(2^(-1/4)))*(1+(2^(-1/2)))答案是1/(2-(2^(7/8))】
一道高一的数学计算题
(1+(2^(-1/8)))*(1+(2^(-1/4)))*(1+(2^(-1/2)))
答案是1/(2-(2^(7/8))
1回答
2020-04-11 18:57
【一道高一的数学计算题(1+(2^(-1/8)))*(1+(2^(-1/4)))*(1+(2^(-1/2)))答案是1/(2-(2^(7/8))】
一道高一的数学计算题
(1+(2^(-1/8)))*(1+(2^(-1/4)))*(1+(2^(-1/2)))
答案是1/(2-(2^(7/8))
设t=2^(1/8),则2^(1/4)=t^2,2^(1/2)=t^4,t^8=2(1+(2^(-1/8)))*(1+(2^(-1/4)))*(1+(2^(-1/2)))=(1+1/2^(1/8))*(1+1/2^(1/4))*(1+1/2(1/2))=(1+1/t)(1+1/t^2)(1+1/t^4)=(t+1)(t^2+1)(t^4+1)/t^7=(...