📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!
  • google app store apple app store
    • ✖

      Question

      src="https://www.ixambee.com/questionimage/Railway-Protection-Force-(RPF)-Constable/1722079503-26.JPG" alt="" />
      A √(k – 2) Correct Answer Incorrect Answer
      B √(k + 2) Correct Answer Incorrect Answer
      C k – 2 Correct Answer Incorrect Answer
      D k + 2 Correct Answer Incorrect Answer

      Solution

      If x2n +1/x2n =k Let xn -1/xn =y (xn +1/xn)2 = x2n +1/x2n +2 (xn +1/xn)2 =k+2                 Let xn +1/xn =z z2 = k+2 … (1) Using the identity for the square of a difference: y² = z2-4 Since     z2 =k+2: y² = (k+2)-4 y² = k -2 Therefore- y = √ k-2 xn -1/xn =√ (k-2)

      Practice Next
      More Algebra Questions

      Relevant for Exams:

      ask-question