Question:
If x + 1/x = 5, find x² + 1/x².
यदि x + 1/x = 5 है, तो x² + 1/x² ज्ञात करें।
Options:
- a) 21
- b) 23
- c) 25
- d) 27
- a) 21
- b) 23
- c) 25
- d) 27
correct answer : b)
Explanation:
x² + 1/x² = (x + 1/x)² − 2 = 5² − 2 = 25 − 2 = 23.
x² + 1/x² = (x + 1/x)² − 2 = 5² − 2 = 25 − 2 = 23।