Discuss Forum
1. x + 1x = 4 হলে x4 + 1x4 এর মান কত?
- A. 149
- B. 149
- C. 149
- D. 149
Answer: Option B
Explanation:
x + 1/x = 2 হলে,
x4 + 1/x4
= (x2)2 + (1/x2)2
= (x2 + 1/x2)2 - 2.x.1/x
= {(x + 1/x)2 - 2.x.1/x}2 - 2
= {(4)2 - 2}2 - 2
= (16 - 2)2 - 2
= (14)2 - 2
= 196 - 2
= 194 (Ans)
Post your comments here: