1.

If x = √3 + √2, then find the value of [x4 + (1/x)4].1. 1002. 983. 1984. 196

Answer» Correct Answer - Option 2 : 98

Given:

x = √3 + √2

Formula used:

(a + b)2 = a2 + 2ab + b2

Calculation:

x = √3 + √2

⇒ 1/x = 1/(√3 + √2)

⇒ [1/(√3 + √2)] × [(√3 - √2)/(√3 - √2)]

⇒ (√3 - √2)

⇒ [x + (1/x)] = √3 + √2 + √3 - √2

⇒ [x + (1/x)] = 2√3

x2 + (1/x)2 = (2√3)2 – 2

⇒ 10

x4 + (1/x)4 = [x + (1/x)]2 – 2

⇒ 102 – 2

⇒ 100 – 2

⇒ 98

∴ x4 + (1/x)4 = 98.


Discussion

No Comment Found

Related InterviewSolutions