If x^2 + 1/x^2 = 27, find the positive value of x – 1/x.
A3
B4
C5
D6
Explanation
(x – 1/x)^2 = x^2 + 1/x^2 – 2 = 27 – 2 = 25 => x – 1/x = sqrt(25) = 5.
Exam Relevance
- Topic: Algebra
- Subtopic: Identities
No Comments