求,一道数学题怎么做啊,求解答,我很需要答案啊,谢谢啊!!!!

2025-05-23 20:54:11
推荐回答(1个)
回答(1):

证明:
x= 1 / (√3+√2)=√3-√2
1/x=√3+√2
所以:x+1/x=2√3
两边平方:
x^2+1/x^2+2=12
所以:x^2+1/x^2=10

所以:
x^5+x^4-10x^3-10x^2+x+1
=(x+1)x^4-10(x+1)x^2+(x+1)
=(x+1)(x^4-10x^2+1)
=(x+1)(x^2-10+1/x^2)*(x^2)
=(x+1)*(10-10)*(x^2)
=0
命题得证