Question

Yuyun語云

這題忘記解法了

1
9. 已知x-3x+1=0,則x+
解
d->d+1=0
d=1
X=3±√9-4
2
2
x
D
3+√5
(opping)
x²-3x=1
二-H3X
2= INF-1
0^-1
N`N
1/
2
3X++z=38-x+
(X-X

Answer 1

Mer

因為x≠0，所以等式可以除以x
x - 3 + 1/x = 0
x + 1/x = 3
(x + 1/x)^2 = x^2 + 2 +(1/x)^2 = 9
x^2 + (1/x)^2 = 7