arrow
arrow
arrow
​(x+1x)(x−1x)(x2+1x2)(x4+1x4)(x + \frac{1}{x})(x - \frac{1}{x})(x^2 + \frac{1}{x^2})(x^4 + \frac{1}{x^4})(x+x1​)(x−x1​)(x2+x21​)(x4+x41​) is equa
Question

(x+1x)(x1x)(x2+1x2)(x4+1x4)(x + \frac{1}{x})(x - \frac{1}{x})(x^2 + \frac{1}{x^2})(x^4 + \frac{1}{x^4}) is equal to:​

A.

x81x8x^8 - \frac{1}{x^8}​​

B.

x41x4x^4 - \frac{1}{x^4}​​

C.

x101x10x^{10} - \frac{1}{x^{10}}​​

D.

x61x6x^6 - \frac{1}{x^6}​​

Correct option is A

Given: 

(x+1x)(x1x)(x2+1x2)(x4+1x4)(x + \frac{1}{x})(x - \frac{1}{x})(x^2 + \frac{1}{x^2})(x^4 + \frac{1}{x^4}) 

Formula Used: 

a2b2=(a+b)(ab)a^2 - b^2 =(a+b)(a-b) 

Solution: 

(x+1x)(x1x)(x2+1x2)(x4+1x4) =(x21x2)(x2+1x2)(x4+1x4) =(x41x4)(x4+1x4) =x81x8(x + \frac{1}{x})(x - \frac{1}{x})(x^2 + \frac{1}{x^2})(x^4 + \frac{1}{x^4}) \\ \ \\ = (x^2 - \frac{1}{x^2})(x^2 + \frac{1}{x^2})(x^4 + \frac{1}{x^4}) \\ \ \\ = (x^4 - \frac{1}{x^4})(x^4 + \frac{1}{x^4}) \\ \ \\ = x^8 - \frac{1}{x^8}​​

Free Tests

Free
Must Attempt

RRB NTPC UG Level PYP (Held on 7 Aug 2025 S1)

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

CBT-1 Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
Free
Must Attempt

RRB Group D Full Mock Test 1

languageIcon English
  • pdpQsnIcon100 Questions
  • pdpsheetsIcon100 Marks
  • timerIcon90 Mins
languageIcon English
test-prime-package

Access ‘RRB Technician Grade 3’ Mock Tests with

  • 60000+ Mocks and Previous Year Papers
  • Unlimited Re-Attempts
  • Personalised Report Card
  • 500% Refund on Final Selection
  • Largest Community
students-icon
446k+ students have already unlocked exclusive benefits with Test Prime!
Our Plans
Monthsup-arrow