已知实数X,满足X^2-2X乘根号2+1=0,求X-1/X的值?

Question

已知实数X,满足X^2-2X乘根号2+1=0,求X-1/X的值?

Answer 1

你用笔写下来：将等式两边同时除以X,得X-2*根号2+1/X=0 整理得：X+1/X=2*根号2. 两边同时平方得：（X+1/X）=8. 展开得X^2+2+1/X^2=8,移项得： X^2+1/X^2=6. 将所求的整个式子括起来平方得（X-1/X）^2 展...